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

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