I can’t figure out what type of vitamin D supplement to buy. There appear to be many different kinds with confusing labels.
Some had names that made references to sunlight, but I still wasn’t sure. You discussed a few posts back what to look for in a fish oil supplement, but what about vitamin D?
Also, my boyfriend works outside (we live in Austin, Texas). He doesn’t tolerate milk, but he eats cheese.
Should he take a vitamin D supplement also, or does he likely get enough sun exposure from being outside all day?
— Kristin Macbride
Via the blog
Despite all the marketing hype you see, there isn’t much diversity in the Vitamin D supplement market.
There are only two different types you can purchase — vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).
While vitamin D2 is a yeast or fungus-based vegan form, supplemental vitamin D3 is synthesized from lanolin, a substance obtained from sheep’s sebaceous glands.
It was initially believed that vitamin D3 was more efficient because it raised serum levels of 25(OH)D (25-hydroxyvitamin D, which reflects vitamin D status in blood) more efficiently that vitamin D2.
The latest research, however, shows no difference between both forms if they are supplemented on a daily basis at a rate of 1,000 International Units per day.
Remember — vitamin D is a fat-soluble vitamin, so you need to take your supplement with a meal that contains some fat (as little as 3 grams).
Taking a vitamin D supplement with a glass of water three hours after dinner before going to bed doesn’t accomplish anything.
As for your boyfriend’s situation: since you live in a geographical area where UVB rays (the ones necessary for skin synthesis of vitamin D) reach you year-round, he doesn’t need to supplement if he is exposed to thirty minutes of sunlight (without sunscreen protection) on approximately forty to fifty percent of his body between the hours of 10 AM and 2 PM.