photo credit: treehouse1977

The summer is almost over and it is back to school time. Hopefully you got a chance to soak up the sun and enjoy some time off with your family. Chances are you were liberal with the sunscreen whenever you went out in the sun. That is definitely the conventional wisdom and there is nothing wrong with it. But did you know that getting some sun without the sunscreen is the best way of building up your child’s vitamin D reserves? Now I am sure you are worried about the damaging effect of too much sun on your child’s tender skin. But it does not take much to get a healthy dose of vitamin D.

I shook my head in disbelief when I read that even in sunny Florida, sub-optimal levels of vitamin D, and even deficiency of vitamin D, are quite common. On a recent discussion about vitamin D on LinkedIn, Diane Batshaw Eisman, MD FAAP wrote:

I am amazed that I find very low levels of Vit D here in Florida. I think we listen to the dermatologists and the natives avoid too much sun and then slather on the sunscreen.

There is some truth to the notion of slathering on the sunscreen because of the strong health advisory and heavy advertising by the makers of sunscreen. There is very little voice to the notion of getting your vitamin D from the sun. After all, who would want to risk advising people to stay out in the sun without sunscreen just to get vitamin D but end up getting melanomas?

Getting vitamin D from the sun appears to be a well kept secret! Experts have even developed a mathematical relationship between the amount of sun exposure and vitamin D. Holick’s rule is well known in the academic circles:

Sun exposure of 1/4 of a minimum erythemal dose (MED) over 1/4 of a body is equivalent to 1000 IU of oral vitamin D3

Minimum erythemal dose is the amount of energy required to produce the first visible sign of redness with clearly defined borders on your skin. In short, this is when you are about to get a burning sensation. The value of MED depends on the skin type – low for very fair skin and high for very dark skin. There are 6 different skin types defined based on the amount of pigment (fair vs. dark) and how easily it burns under the sun. The more popular UV Index is designed based on MED – for example, a type II skin will receive 1 MED within 20 minutes at a UV index of 10. To get a 1/4 of the MED, they would need to be in the sun for only 5 minutes, which means they can get 1000 IU of vitamin D3 in just 5 minutes with their arms and legs exposed without sunscreen! Consider this when the current recommended amount for toddlers is only 400 IU per day.

These calculations are not exact and actual exposure numbers may be different. The point is that it does not take much to get your daily quota of vitamin D3 from the sun. Of course, it is important to use good judgment and common sense not to overexpose the unprotected skin.

We live in a world where the solution to all our problems comes in a pill! For centuries, we have survived by getting this essential nutrient from the sun and diet – in fact, our skin color evolved in response to the amount of available sunlight. In the 21^st century, they now want you to believe that sunlight is too dangerous and that you should solve your vitamin D problem by popping a pill each day.

What do you think? Should the public health message about sun and sunscreen change?

©2010 Littlestomaks.com

photo credit: sly06

A recent article in the Pediatricss journal reported data on serum levels of 25-hydroxyvitamin D, the active form of vitamin D in blood and asked this question Do Children Need More vitamin D? There is a lot of buzz in the media these days about deficiency of vitamin D, especially in kids. Beyond the screaming headlines and soundbites, it is important to look at the data an scientific way before jumping to conclusions.

In this article,  I will first provide a brief background on vitamin D and explain why it is a concern these days especially for growing children. Second, I will describe the design of the Pediatric study and methods used to analyze data. Finally, I will summarize the results to support some of the key conclusions of this study.

Let me first say that there is no consensus on the threshold level of vitamin D in blood below which a child is considered deficient. Still, the authors concluded that millions of US children aged 1-11 years may have sub-optimal levels of vitamin D, especially non-Hispanic Black and Hispanic children. However, more research is needed before a decision can be made about recommending vitamin D supplementation in children.

Vitamin D – the sunshine vitamin!

Vitamin D is produced when our skin is exposed to the UV-B rays from the sun. That is why, sometimes it is also called the sunshine vitamin. It is also available from a few limited food sources such as milk, fortified orange juice and cereals, and fish such as salmon, mackerel, cod and herring. Vitamin D supplements are also available from both synthetic and natural sources. Deficiency of vitamin D is known to cause rickets, a condition which involves bone loss and deformation. Because vitamin D is also a prohormone, meaning it is involved in proper functioning of other hormones, recent research is linking vitamin D deficiency with many other diseases like diabetes, heart disease and even cancer.

Why the concern then? Well, the problem is that many parts of the world do not get enough sunlight through the year. When we do manage to get some sun, we have a tendency to overuse sunscreen because of the risk of skin cancer. Don’t stop doing that, but be aware that sunscreen blocks the UVB rays responsible for vitamin D production. As for nutrition, we know that children are picky eaters. They hardly eat fish or drink enough milk. Junk food has little vitamin D. Because of these reasons, there is a concern that kids are not getting enough vitamin D.

The Pediatrics study analyzed 2001-2006 NHANES data for kids 1-11 years old

Because of the concern over vitamin D, the Pediatrics article is very timely. Researchers from Harvard, Mass General Hospital and University of Colorado analyzed the NHANES data from 2001 – 2006, which is collected every 2 years by the National Center for Health Statistics. The NHANES uses a 4-stage sampling strategy to represent households across the country. It tends to oversample low income groups, blacks and Mexican Americans. However, statistical methods including appropriate weights are available to extrapolate the results to a nationally representative population.

In this study, the researchers obtained serum levels of 25-hydroxy-vitamin D – the “active” form of vitamin D present in the blood. They also had household interview data about the demographic, socio-economic status and vitamin use. Sample size for kids 6-11 years old from 2001-2006 was 3421 for household interview data and 2759 for serum 25(OH)D data. Sample size for kids 1-5 years old from 2003 – 2006 was 2677 for household interview data and 1799 for serum 25(OH)D data.

Serum levels were categorized as <25, <50 and <75 nmol/L. Although, there is no consensus on what constitutes as the level of deficiency in children, the Institute of Medicine has set it at less than 27.5 nmol/L while the Canadian Pediatric Society has set it at less than 25 nmol/L. Recently, a level of less than 50 nmol/L has been found to be linked to some level of bone demineralization.  In adults, recent studies demonstrated that healthy levels of serum 25(OH)D may be as high as 75 nmol/L or even higher. That is why, the researchers decided to look at prevalence data for the nationally representative population of 1-11 years old children at these 3 different levels.

Average blood levels do not show deficiency, but experts believe most kids have lower than desired level of vitamin D

The mean serum level for children 1-11 was 68 nmol/L. Children aged 6-11 had a slightly lower mean level at 66 compared to those aged 1-5 at 70 nmol/L.

When taken as a whole, following prevalence levels were found:
< 25 = 1%, < 50 = 18% and < 75 = 69%

In terms of actual population numbers, this translates to 320,000 children below less than 25, 6.3 million less than 50 and 24 million less than 75. If the “average” values of the serum level gave you a sense of comfort, simply look at these prevalence numbers. Amazing!

If you consider the level of 75 nmol/L or higher as optimal, like most experts, the prevalence of serum levels below 75 was higher for non-Hispanic blacks at 92% and Hispanic at 80% compared to non-Hispanic white children at 59%. In terms of numbers, 2 out of every 3 children in the US are below this level, and nearly all of the non-Hispanic black and Hispanic children are below this threshold. If the threshold is changed to <50, then over half of non-Hispanic black children 6-11 years old fall in this category.

The current daily recommended intake from the Academy of Pediatrics is 400 IU/day. Experts believe that this is insufficient to raise the serum levels to >50 or >75 and that vitamin D supplementation may be needed in at-risk populations.

More vitamin D is good for children, but do not jump to supplements right away!

Coming back to the original question “do children need more vitamin D”, the short answer is YES. It may be tempting to simply get on a daily supplement. But I think we should try to first make small changes in our lifestyle and eating patterns. Nature did not intend us to be deficient in vitamin D, even though she gave us all a different skin color. The fact that we see low numbers in our population is a result of our lifestyle and poor diet. Get active, get outdoors – even 10-15 minutes of sun exposure on your arms and legs without sunscreen is enough. Of course, you should worry about skin cancer and use sunscreen before it is too late. Get your kids to eat healthy including a diet rich in dairy and fish unless there is an allergy problem. There are many natural ways to ensure your child gets enough vitamin D before deciding to take a supplement.

Parents – are you concerned that your child may have a vitamin D deficiency? What steps are you planning to take? Share in your comments below.

©2010 Littlestomaks.com

There is a lot of buzz about vitamin D deficiency these days. According to some reports, 40% of US infants and toddlers are not getting enough vitamin D which increases their risk of a variety of health conditions. No doubt, vitamin D is very important for health,  especially for growing children. That is why it is good to pay attention to your child’s needs but there is no need to panic. In the past, I have written several articles on vitamin D including 5 ways to tell if your child may have a vitamin D problem. Here, a few quick facts about this important vitamin:

1. Vitamin D actually is a prohormone; which means that it is converted into a hormone inside the body. In this way, it is different from all other vitamins.
2. Vitamin D is produced when our skin is exposed to UVB rays from the sun.
3. There isn’t enough UV energy above 42 degree north latitude (a line between northern California and Boston) during November to February to produce any vitamin D in the skin. In places farther north, this can last nearly 6 months during the year.
4. Vitamin D from food or supplements comes in 2 forms – vitamin D2 or vitamin D3.
5. Vitamin D3 is 3 times more effective than vitamin D2 in maintaining blood levels of the active form of vitamin D.
6. Vitamin D is fat soluble and any excess from sun exposure or diet is stored in fat cells available for release when blood levels fall low especially during winter months. This does not, however, happen very easily in overweight or obese individuals.
7. American Academy of Pediatrics recommends a daily value of 400 IU for young children. You can get this amount from 4 glasses of milk or vitamin D fortified orange juice, 1.5 oz of cooked salmon, or about a third table spoon of cod liver oil.
8. Vitamin D deficiency causes rickets in children. Recent research indicates a link between vitamin D deficiency and diabetes, heart disease and certain types of cancers.
9. Blood levels of less than 20 ng/ml are considered to indicate vitamin D deficiency.
10. Mushrooms when exposed to UV light during production are rich in vitamin D2.

Source: Vitamin D Dietary Supplement Facts Sheet from NIH

Plenty of news about deficiency of vitamin D in children these days and plenty of advice on how to get it from foods like fish and milk or supplements. But did you know that UV light zapped mushrooms are full of vitamin D? UV light from the sun is what makes vitamin D in our own skin. This is a great way to enhance the vitamin D content of mushrooms without any additives. Mushrooms are also a good source of vitamin B, iron, protein and fiber.

This is good news for those who may be allergic to fish or dairy, or simply want to look for more options before getting on the vitamin D supplements bandwagon. The US Department of Agriculture has been actively developing a method to treat common mushrooms (white, portobello etc.) with help from Monterey Mushrooms, a large national-level producers of fresh mushrooms. Although, we have not stumbled upon it in our local store, they now have the  Sun Bella brand UV-treated mushrooms available in major supermarkets nationwide.

There is another competing method of treating mushrooms using high energy flashes of UV light. This patent-pending method has been developed by the Xenon Corporation and used by Dole in treating their portobello mushrooms. I am sure they will soon hit the store shelves all over if not already there.

The reason it works is that mushrooms contain a sterol (a class of chemical compounds, for example cholesterol) called ergosterol, which is converted to vitamin D2 (also known as ergocalciferol) when it is exposed to UV light. It appears that a strong focused exposure to UV light is needed for conversion because it does not happen on its own when mushrooms are cultivated.

The other form of  vitamin D available from food, especially animal sources, is vitamin D3 (also known as cholecalciferol). Vitamin D3 is more effective than vitamin D2 in raising the blood levels measured in a typical test.

I think this is great news, although I am sure these companies will charge a premium for the vitamin D “enhanced” mushrooms. Look for them in your supermarkets and let me know if you come across any other brands.

Photo source: Wikimedia
©2009 Littlestomaks.com

News of vitamin D deficiency in children are popular in the media these days. Like all concerned parents, I am sure you have paused to pay attention to these news and wondered if you should get a vitamin D supplement for your toddler. The only way you can be sure whether your child has a vitamin D deficiency is by getting a blood test which screens for a particular form of vitamin D called 25-hydroxyvitamin D. Unfortunately, there are no early warning symptoms which can help you determine if you should take a corrective action.

You don’t need to go rushing for a blood test right away though! By paying attention to your child’s general level of outdoor activity and eating patterns, you can get a few clues. Here are 5 questions you can ask to figure out if there might be a need to get a definitive answer on vitamin D deficiency in your specific situation. However, you should not jump to a conclusion too soon just by observing over a few days. Rather you should try to look for a general pattern over a period of time.

Does he get enough time to play in the sun?

Your child’s body (and yours) is programmed to make its own vitamin D simply by being out in the sun. Even 10-15 minutes of play with arms and legs exposed to the sun can be enough. And best of all, the body is able to self-regulate the amount of vitamin D by storing the excess in fat cells.

The problem is that you may not get enough sunshine during the day, especially during the fall and winter months simply because of where you live. Children with darker skins are also at a disadvantage because of the pigment in their skin which absorbs the UVB rays which would otherwise be used to make vitamin D.

The good news is that the effect of sun is cumulative - that is, it adds up over time. Take advantage of every sunny day, even in the middle of winter to let your child play outside. Getting fresh air and physical exercise is good not only from the point of vitamin D, but also for overall physical and emotional health.

Does she drink at least 4 cups of milk every day?

Milk, by far, is the best source of vitamin D because all milk in the US is now fortified with vitamin D. However you need at least 4 cups to reach the recommended level of daily vitamin D (400 IU for children).

The problem could be milk allergies and just a natural dislike of milk. Also 4 cups is a lot, and even adults don’t usually get to drink that much on a daily basis. Try to mix with vitamin D fortified cereals, most of them generally are these days. You can also get vitamin D fortified orange juice, but be sure to watch out for added sugar.

One good way of increasing milk consumption is to add it to a smoothie. This way you can also get your child to eat some fruits!

Does he eat fish as part of a balanced diet?

Eating fish such as salmon is almost like buying insurance as far as vitamin D is concerned. You don’t have to eat it everyday – even once a week can work its magic. One serving of 3.5 oz (about 100g) or the size of a deck of cards can provide as much 2 times or even higher than the daily recommended level of vitamin D. Other fishes like tuna, mackerel and sardines are also good sources of vitamin D. Mercury contamination is a risk but should not be too much of a concern if you eat them occasionally as part of a varied diet.

The problem again could be allergies. Also your child may not like the taste or smell of fish. Trying new recipes and offering in small portions in combination with some of his other favorites can help you to build a taste for fish.

Does she seem overweight for her age?

Childhood obesity is on the rise and if your child is overweight or obese, you have a challenge in terms of vitamin D as well. That is because the body is not able to pull the vitamin D stored in the fat cells when needed.

Keep a close eye on her Body Mass Index by looking at the age specific growth charts. They are available on the CDC website or you can ask your pediatrician. Again, it is important to look at the trend and not a single point on these charts. If you see a trend creeping over the 85th percentile, you need to take action right away and improve the overall nutrition and eating habits of your child. Unless there is an underlying medical condition, nutrition and lifestyle changes can show good results.

Does he have special medical conditions?

In the most unfortunate situation, your child may have a medical condition such as Crohn’s disease, celiac disease or cystic fibrosis. These diseases cause poor absorption. Since vitamin D is a fat soluble vitamin, its availability is severely reduced in people suffering from these problems.

If this is the case, you are probably already talking to your pediatrician. Discuss the matter of vitamin D deficiency if you have not already done so.

After considering your specific situation, you can consult with your pediatrician about supplements. While I am not a fan of jumping on the vitamin supplements bandwagon, I think it is important to be informed about them. I plan to write about vitamin D supplements in future once I have had a chance to do some research on them.

What do you think? Are you concerned about your child’s vitamin D levels? Are you considering supplements? I would love to hear your comments.

Photo Source: Leo Reynolds on Flickr
©2009 Littlestomaks.com

The media was abuzz this week with screaming headlines warning us of widespread vitamin D deficiency in kids. It followed a recent paper in the Pediatrics journal by researchers at the Children’s hospital in Boston, Massachusetts General Hospital, Harvard Medical School and the University of Colorado. The paper presented their research based on the 2001-2004 NHANES survey and posed the question Do Children Need More Vitamin D?

That the mainstream media latched on this latest research and gave it prime time coverage is not a surprise to me. I have written about such attention grabbing headlines on vitamin D before. I am so intrigued by the popularity of this topic in the press that I decided to look at this week’s news in more detail for today’s Five for Fridays. I would love to hear your comments and concerns about vitamin D for your children.

Here are 5 reasons why I believe we don’t need to let the mass media engulf us in mass hysteria about vitamin D:

There is no consensus on healthy levels of vitamin D in children

The Pediatrics paper correctly points out that:

There is controversy, however, about what a healthy level of 25-hydroxyvitamin D is for children and even what level of 25(OH)D should be used to define vitamin D deficiency

25-hydroxyvitamin D is what they measure in the blood to determine the level of vitamin D. Different agencies have defined vitamin D deficiency as blood levels less than 27.5 to 37.5 nmol/L. Many experts today believe that these levels are too low and should be revised to less than 50 nmol/L or even 70 nmol/L. By raising the number on the “safe” level, these experts suggest that a lot more people should be considered vitamin D deficient compared to current standards.

While there is some data to suggest various benefits of higher levels of vitamin D in adults (75 to 100 nmol/L), there is no such evidence and consensus for children. When even experts cannot agree on “safe” levels of vitamin D in children, I am not sure if it makes sense to raise a red flag based on this week’s report.

Average vitamin D levels in children are much higher than currently recommended

Amazingly, the Pediatrics paper reports that the average blood level of 25-hydroxyvitamin D was 70 nmol/L. Further, prevalence for levels less than 25 nmol/L was only 0.7% and that for levels less than 50 nmol/L was 15%. It is only when you consider a level of 70 nmol/L as the “safe” level that the prevalence goes up to 65%. Basically that means that most children have a sufficiently high level of vitamin D.

I am not suggesting that we should not worry about the 15% or so who had levels lower than 50 nmol/L. It is a cause for concern, but probably not as much as the rate of childhood obesity. The problem I have with these studies is that they tend to look at only one thing at a time and lose the big picture on our children’s health.

Perceived risks based on geography and ethnicity do not justify broad changes

We have all heard the usual reasons for low vitamin D – children do not get enough time in the sun which makes things worse for dark-skinned children of Hispanic and African-American background. Also children who live in the Northern altitudes do not get enough sun particularly in the winter months.

These observations are all true. However, aside from skin color and average sun exposure there is also an effect of poor nutrition in general. It is probably not a conincidence that children in these same demographic groups have also been reported as either overweight or obese. Under these circumstances, even if these children were put on vitamin D supplements, I am not convinced that it will do anything to improve their prospects of future health. I think that a narrow focus on vitamin D misses the big picture on children’s nutrition.

Based on these studies alone, I don’t think a sweeping across the board recommendation of higher vitamin D can be justified.

There is no evidence for preventive powers of vitamin D by large randomized clinical trials

A fascinating article appeard in last week’s Financial Times which posed the question To D or not to D? Recent research reports a link between higher vitamin D and lower risk of certain types of cancer. On the flip side, low levels of vitamin D have been reported to increase the risk of osteoporosis, heart disease, multiple sclerosis, type 1 diabetes, depression and rheumatoid arthritis. One recent review of health records of over 13000 Americans found that people with the lowest vitamin D levels were 26% more likely to die in an 8 year period compared to those with the highest levels.

How can you not have the sense of urgency about recommending everybody to have higher vitamin D? It seems like a no brainer.

Not so fast say the international health authorities! Even the International Agency for Cancer Research of the WHO issued a report last year that basically concluded there was no need to raise vitamin D recommendations. The Institute of Medicine in the US also does not appear to be in any hurry to change the current recommendations.

The main reason for this reluctance is that the preventive power of vitamin D has not yet been proven by large scale randomized clinical trials. The Financial Times article provides a good understanding of why such clinical trials may never take place. There are some clinical trials going on for senior citizens, but nothing on the horizon for children or young adults.

I am impressed by the commitment of today’s vitamin D researchers. However, I think there ambitions are out of proportion with their findings. I have nothing against targeted intervention in high risk groups, but it is meaningless to stretch the recommendations to everybody across the board.

These studies imply relying on supplements instead of nutrition and active lifestyle

Finally, this is the main reason why I am not a big fan of these studies. The underlying implication is that we can easily solve this problem by vitamin D supplements. The Pediatrics paper asks the question:

Considering these prevalence data, would there be risks associated with recommending that all children have vitamin D supplements until the short- and long-term health outcome data are elucidated?

It does address the concern about vitamin D toxicity but suggests that it is rare and happens only when really excessive doses of vitamin D are taken. Clearly, their agenda is to promote vitamin D supplements for children:

As suggested recently by the Canadian Pediatric Society and a recent stateof-the-art review on vitamin D, higher supplement doses may be required for children to reach the safe and potentially healthier levels of 25(OH)D of <50 or <75 nmol/L.

I think there is a real danger in such linear thinking. Instead of promoting healthy nutrition and physical activity first, and nutritional supplements second, the supplements are considered a primary means to good health. I reject that notion even though these studies get very high profile coverage in the press.

I am glad that a few Moms I talked to on Twitter about this topic calmly suggested that the real solution is to get your children to eat well, drink plenty of milk and play outdoors. At least they are not falling for this propoganda!

Have a good weekend and do let me know what is on your mind.

Photo Source: Wikimedia Commons
©2009 Littlestomaks.com

Ask The Expert is a weekly column on Littlestomaks.com. The idea is to have a reader-submitted question answered by a nutrition expert or a pediatrician. Feel free to submit your question in the comments section below.

This week, Family Physician and Registered Dietitian Dr. Shelley Meyer explains the recommended levels of vitamin D and A for a toddler.

Question: What is a safe level of vitamins D and A to give a 31 month child that weighs about 40 pounds?

Answer:

Vitamins A and D are fat-soluble vitamins, quite essential to children’s diets.  Vitamin D has been a particularly hot topic in the news lately, due to recent findings that a lot of Americans are deficient, including toddlers and children.  Vitamin D is needed for healthy bones, and a deficiency can cause soft, weakened bones known as rickets, and even lead to osteoporosis.  The recommended daily intake of Vitamin D for infants, toddlers and children has recently been increased from 200 IU to 400 IU.  Sunshine is needed to make Vitamin D into its active form, and little ones tend to be covered in sunscreen to protect their delicate skin, therefore explaining how potential deficiencies can occur.  However, only 10-15 minutes per day is needed to activate this essential vitamin.

It is important to remember that food sources are always better absorbed by the body than supplements.   However, if your child is a picky eater and does not drink Vitamin D fortified milk or eat foods rich in Vitamin D, such as fish and egg yolks, then it can be difficult to meet the daily requirements.  In this case, a simple daily dose of a multivitamin or a 400 IU Vitamin D supplement will suffice.

Vitamin A is generally found in abundance, as long as your child or toddler will eat fruits and vegetables.  Vitamin A is essential for healthy eyes, skin, teeth and bones.  Good sources of Vitamin A are eggs, milk, dairy, carrots, sweet potatoes, cantaloupe and dark green vegetables .   Vitamin A can be toxic in excessive amounts so it is important not to exceed the amount found in a multivitamin, generally 2500 retinol equivalent.

©2009 Littlestomaks.com. All Rights Reserved

Disclaimer – Information provided in Ask The Expert column on Littlestomaks.com is intended to give you general guidance on a question related to toddler nutrition. It is not meant to be treated as medical advice. You are welcome to contact this expert for a detailed consultation on your specific situation to determine what actions, if any, you should take regarding nutrition and health of your toddlers. We do not recommend you to take any action based solely on the information presented in this column. Experts have agreed to provide their professional opinion on toddler nutrition related questions on a voluntary basis and no compensation is offered to them by Littlestomaks.com.

Ask The Expert is a weekly column on Littlestomaks.com. The idea is to have a reader-submitted question answered by a nutrition expert or a pediatrician. Feel free to submit your question in the comments section below.

This week, Registered Dietitian Preethi Rahul explains how you can manage the vitamin D intake of breastfed infants and children.

Question:Is it true that breastfed babies need more vitamin D and can it be obtained through breast milk if the mother increases her vitamin D intake?

Answer:

Yes! Definitely breastfed babies need more vitamin D as human milk contains five metabolites of Vitamin D, providing 40-50 IU/ L of vitamin D activity. The need for additional vitamin D becomes progressively important with increasing age. Cow’s milk is usually fortified with 400 IU/L of vitamin D.

Vitamin D does not occur naturally in foods that humans normally eat. Moreover, the widespread use of sunscreens and public health recommendations to avoid sun exposure reduces dermal synthesis of vitamin D₃. Most people therefore get vitamin D₃ by taking a vitamin D supplement or by consuming vitamin D–fortified milk.

Vitamin D is undoubtedly important for fetal development and for bone development in childhood; it plays a much wider role in health and disease prevention. Vitamin D is essential for cell differentiation, the functional maintenance of membranes, as well as the functions of several organs including skin, muscle, pancreas, nerves, parathyroid gland and the immune system. It is important to understand that vitamin D is not really a vitamin; vitamin D₃ is a pre-pro hormone made in the skin in response to ultraviolet-B light exposure. Vitamin D3 is the precursor to form 25-hydroxyvitamin D₃ [25(OH)D₃], a pre hormone, which is ultimately converted to 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃]. One of the most potent steroid hormones known, 1,25(OH)₂D has the capacity to affect many bodily functions beyond calcium metabolism.

All infant formulas sold in the United States must have a minimum vitamin D concentration of 40 IU/100 kcal (258 IU/L of a 20 kcal/oz formula) and a maximum vitamin D3 concentration of 100 IU/100 kcal (666 IU/L of a 20 kcal/oz formula).All formulas sold in the United States have at least 400 IU/L of vitamin D₃. Because most formula-fed infants ingest nearly 1 L or 1 qt of formula per day after the first month of life, they will achieve a vitamin D intake of 400 IU/day. Infants who receive a mixture of human milk and formula also should get a vitamin D supplement of 400 IU/day to ensure an adequate intake. As infants are weaned from breastfeeding and/or formula, intake of vitamin D–fortified milk should be encouraged to provide at least 400 IU/day of vitamin D.

Although vitamin D concentrations can be increased in milk of lactating women by using large vitamin D supplements, such high-dose supplementation studies in lactating women must be validated and demonstrated to be safe in larger, more representative populations of women across the world. Recommendations to universally supplement breastfeeding mothers with high dose vitamin D cannot be made at this time. Therefore, supplements given to the infant are necessary.

Check out the following articles related articles on vitamin D

Ask the Expert – Vitamin D Deficiency
40% of infants and toddlers have vitamin D deficiency – should you worry?
5 reasons to consider a multivitamin supplement

©2009 Littlestomaks.com. All Rights Reserved
Disclaimer – Information provided in Ask The Expert column on Littlestomaks.com is intended to give you general guidance on a question related to toddler nutrition. It is not meant to be treated as medical advice. You are welcome to contact this expert for a detailed consultation on your specific situation to determine what actions, if any, you should take regarding nutrition and health of your toddlers. We do not recommend you to take any action based solely on the information presented in this column. Experts have agreed to provide their professional opinion on toddler nutrition related questions on a voluntary basis and no compensation is offered to them by Littlestomaks.com.

Ask The Expert is a weekly column on Littlestomaks.com. The idea is to have a reader-submitted question answered by a nutrition expert or a pediatrician. Feel free to submit your question in the comments section below.

This week, Pediatrician Dr. Joanna Dolgoff explains how you can find out if your child is vitamin D deficient.

Joanna Dolgoff, M.D. BA Molecular Biology, Princeton, Graduated Cum Laude MD, NYU School of Medicine Pediatric internship and residency at Presbyterian Children’s Hospital of New York 5 years private practice in Pediatrics CBS News Online correspondent: childhood obesity expert Child & Adolescent obesity and weight management expert Website:Online Weight Management Program Twitter:@joannadolgoffmd LinkedIn Profile Contact: via email from website

Question: How do I know if my child has vitamin D deficiency?

Answer:

New studies are proving that vitamin D is an important nutrient that can help prevent many diseases such as cancer, depression, diabetes, hypertension, osteoporosis, chronic fatigue, autoimmune diseases and cardiovascular disease.

There are a few different ways to get vitamin D.  Vitamin D may come from foods or vitamin supplements; vitamin D can also be made by the skin when it is exposed to ultraviolet rays (UV light).

Vitamin D deficiency is often missed because there are no real symptoms associated with it.  Rickets and osteomalacia (softening of the bones) are the most common signs of vitamin D deficiency but there is no way for parents to tell if their child is suffering from these illnesses.  The only way to prove that your child is vitamin D deficient is by completing a blood test which screens for a particular form of vitamin D, called 25-hydroxyvitamin D (25(OH)D).

Think that name sounds complicated?  Unfortunately, many doctors do too.  In fact, doctors often order the wrong blood test when assessing vitamin D levels.  Be sure to ask for 25(OH) D blood test not 1, 25-dihydroxy-vitamin D (aka calcitriol).  With such complicated names, it is no wonder that such mistakes are made!

Vitamin D deficiency exists when 25(OH) D levels fall below 25 ng/mL.  Levels may vary depending on time of year, direct sunlight exposure, skin color and vitamin D consumption.  Levels should be between 50 – 80 ng/mL year-round for both children and adults.

As a doctor, I am finding more and more children with low levels of vitamin D, mainly because kids are spending less time in the sun.  These days, toddlers are more often inside watching TV than playing outside.  And if they are in the sun, they are lathered with sun block, which reflects the sun’s rays and decreases vitamin D formation.  Obviously, sunscreen is important and should not be avoided!  But it does lead to lower levels of vitamin D. Also, many toddlers do not get enough vitamin D to meet their needs since there are limited food sources of high vitamin D content.

The current recommendation is 400 IU per day in the form of of vitamin D3 (cholecalciferol).    New studies are showing that higher levels may be needed to prevent the diseases discussed above.  Many are now recommending 1,000 IU per day in the form of vitamin D3 (cholecalciferol).  If your child doesn’t get this amount of vitamin D in his diet, you may want to consider a multivitamin that contains vitamin D.

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If you are giving your toddler a couple of cups of milk, vitamin D fortified orange juice, yogurt and cereal, and you take him out to play in the sun for 5 – 30 minutes each day, then there is no reason to worry. And if he has a taste for salmon and tuna, you are in really good shape. There is absolutely no need to grab that fancy multivitamin nutritional supplement on your next shopping trip. Balanced diet and an active, healthy lifestyle works like a charm!

There has been a recent buzz in the media about vitamin D deficiency among infants and toddlers. “Kids Aren’t Getting Enough Vitamin D” screams one headline, while “Vitamin D Deficiency Puts 40% of U.S. Infants and Toddlers at Risk” cries another. It is quite natural to be alarmed by such news; even I paid attention to it and started researching the topic to figure out if our twins were getting enough vitamin D each day.

It is worthwhile to get a little better understanding of why vitamin D deficiency is such a big deal. It is known to cause rickets (softening and twisting of bones in children). Vitamin D is important of absorption of calcium and phosphorus in bones to maintain their strength and proper development. Recent research is also showing that vitamin D plays an important role in prevention of diabetes, multiple sclerosis and certain cancers. It can also cause weakness in muscles if deficient. It seems to influence over 200 genes, including those that regulate cellular proliferation of both normal and cancer cells.

As I read more, I found myself fascinated by the incredible biochemistry that goes on in the body while processing vitamin D from various sources. Sunlight converts cholesterol from skin into vitamin D₃, which is converted inside the liver into another form (25-hydroxyvitamin D) and released into the circulating blood stream. Vitamin D fortified foods can contain D₃ and another form D₂, both of which end up in the liver for conversion to 25-hydroxyvitamin D. By the way, it is the level of this 25-hydroxyvitamin D that tells you if you have a vitamin D deficiency. If this level is between 30 – 60 ng/mL, you have no reason to worry! 25-hydroxyvitamin D now finds its way to the kidneys, where it is converted to the active form 1,25-dihydroxyvitamin D under the influence of hormones from the parathyroid gland. This active form of vitamin D increases calcium absorption in the small intestine. Calcium and phosphorus absorbed in the small intestine are released in the blood, from where they are picked up by the bone cells for bone growth. 1,25-dihydroxyvitamin also regulates the growth and maturity of bone cells, which in turn release back the calcium and phosphorus in the blood to maintain their levels in the circulation system. The whole system works in harmony, promoting controlled bone growth!

You can continue to be vigilant by paying attention to what you buy. Remember that unless the label says Vitamin D fortified, orange juice, yogurt, cheese and cereals do not contain this vitamin. If you have a choice, go for Vitamin D₃ because it is three times more effective than Vitamin D₂ in conversion to 25-hydroxyvitamin D. If the label simply says Vitamin D, then most likely it is Vitamin D₂.

Here are some of the products we use regularly. Looking at them, and how much our twins are getting overall each day, I am not worried about Vitamin D deficiency.

Are you still worried?

If so, discuss with your pediatrician. Depending upon your specific case, you may be able to get advice about a nutritional supplement.

Here are some links for more information:

1. A very technical article in the New England Journal of Medicine
2. Dietary supplement fact sheet on Vitamin D from NIH