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