Category Archives: vitamin D12

Med School Students Know Everything about Nutrition

So today I hopped on this site: http://www.helium.com/items/459838-has-the-widespread-use-of-sunscreen-contributed-to-vitamin-d-deficiency-in

And I started wondering if I could just toss around the word “medical” and write about anything and people would believe me. Now, I’ve seen surgeons who back skin care products and dermatologists advertising dietary supplements (most get the equivalent of 1 semester of nutrition in their education though there are indeed the ones out there who know their stuff) but now I’m reading advice from a medical school student who is telling me about vitamin D12. Now, I’m not sure what the heck vitamin D12 is but maybe I should get some? And, sure that could have been a typo but that wasn’t the worst of of the glaring inaccuracies in her article. I responded (it’s taking some time to go through on this website) but maybe instead of my credentials I should have put Marie Spano, Emory Medical School surrounding area resident (actually I live miles from there but I do drive by the campus once a week)? Prior to throwing out “medical school student,” she should have done her research, especially if she plans to focus on endocrinology or dermatology (yikes).

Here’s my response:

Actually, the information presented here is incorrect. First, it is vitamin D2, not D12. Secondly, vitamin D is actually found in relatively few foods in nature. Plant-wise, mushrooms are your best source. And, as you mentioned, fortified milk, beef, veal, some fatty fish and egg yolks are all good sources.

Another glaring inaccuracy is that sunscreen that protects against UVB rays (and they all do) will indeed prevent sun from reaching the skin. Therefore, it will prevent the process through which our body can make vitamin D upon exposure to sunlight. And actually, according to the research, wearing a sunscreen with a SPF of just 8 blocks vitamin-D producing UVB rays from penetrating your skin (please see the NIH Fact sheet about Vitamin D for more information). So yes, wearing sunscreen will definitely inhibit your body’s production of vitamin D. I do not advocate not wearing sunscreen (especially since I wear it everyday) but the majority of people shouldn’t count on the sun for meeting their vitamin D needs.

In addition to sunscreen inhibiting our body’s production of this vitamin, UVB rays do not penetrate glass so exposure to sun while you are driving your car will not help your body produce vitamin D. Cloud cover, smog and skin melanin content (the pigment that makes skin dark) also affect UV radiation exposure and therefore, our body’s ability to produce vitamin D.

It should come as no surprise, given the few foods that contain vitamin D and lack of production through sun (because of many variables), that a number of people in the U.S. are in fact vitamin D deficient. According to study highlighted on the National Institutes of Health website, many teens today aren’t getting enough vitamin D and half of black teenagers may be vitamin D deficient (http://www.nlm.nih.gov/medlineplus/news/fullstory_81307.html). Infants are also at risk for low vitamin D levels hence the American Academy of Pediatrics doubled the recommendation for infants from 200 IU to 400 IU per day.

Other groups at risk for deficiency include breastfed infants, older adults (older adults are less able to synthesize vitamin D efficiently), individuals with dark skin, people with fat malabsorption issues, people who are obese and those with little sunlight exposure to begin with. There are indeed many groups of individuals who are at risk for low vitamin D levels.

Vitamin D deficiency has been linked to many chronic diseases, soft bones (osteomalcia), osteoporosis, weak muscles, diabetes, immune system problems and some inflammatory diseases.