A new study on vitamin D just came out Tuesday. The study, undertaken by an expert committee (The Institute of Medicine) commissioned by the government, seeked to clarify the issues behind the vitamin D question, namely those of deficiency and supplements.
So far, the findings of the comittee have been highly controversial and even interpreted differently by different parties. Check out the New York Times article on the subject, and the comments as well. A Google search on the Institute of Medicine’s vitamin D study will reveal even more varying interpretations and opinions.
Basically, the committee concluded that evidence of vitamin D deficiency was inconclusive, that vitamin D health benefits apart from bone health were unclear, and that vitamin D supplements, though useful in some cases, could be more harmful than helpful in high doses. The general consensus is that we get enough vitamin D from daily accidental sun exposure and diet. Deliberately exposing oneself to more sunlight, or taking supplemental vitamin D in excess is not recommended.
Some parties praise the study for its balanced set of recommendations. Others condemn it for being too cautious and failing to address the very real problem of vitamin D deficiency across the globe.
Well, who can we believe?
There are many factors to consider when evaluating a study like this. First of all, the study doesn’t seem to take into account various locations on the globe that get less sunlight. There is also no mention of people with darker skin, who need more sun exposure to get the same amount of vitamin D as people with lighter skin. Also, the study posits a lower requirement for average vitamin D levels: 20-30 nanograms, as opposed to higher recommended levels around 40-50. Also, the committee found that only 600 IU of vitamin D was needed daily for most people, while recommended dosages have risen to 1,000 – 2,000 IUs.
The committee didn’t find enough evidence of causality for vitamin D and health benefits, or vitamin D deficiency, but that doesn’t mean these things don’t exist. The members of this comittee were just probably being cautious to avoid encourage people to take excessive amounts of vitamin D supplements that could be damaging, though this is debated as well.
It is important to remember that these scientific studies often contradict themselves as time goes on. Science is a perpetual process of rooting out error and inaccuracy. Is this study accurate? Or are its opponents’ findings more accurate? Still hard to say. We will definitely be following this ongoing inquiry.
In the end, the best rule of thumb for these matters is moderation. We still know that sunshine is the most natural and plentiful source of vitamin D in nature, and that the body naturally regulates vitamin D intake when acquired from the sun. Eat a well balanced diet, and if your doctor thinks you are vitamin D deficient, maybe you should take some supplements, but only as much as needed. Get sunshine when you can, but be reasonable about how much you get, and don’t burn! If your region doesn’t get enough sun or if you work indoors all day and need to tan indoors for the vitamin D, do so responsibly, as tanning salons have always advocated.
Practice moderation and good sense and you’ll surely live a long, prosperous life.