I’ve been convinced for a while that taking vitamin D supplements is worth it, and study after study seems to confirm my choice.
Here’s what the most recent one from the University of California Riverside has to say:
In a paper published in the August issue of the American Journal of Clinical Nutrition, [Anthony Norman, an international expert on vitamin D,] identifies vitamin D’s potential for contributions to good health in the adaptive and innate immune systems, the secretion and regulation of insulin by the pancreas, the heart and blood pressure regulation, muscle strength and brain activity. In addition, access to adequate amounts of vitamin D is believed to be beneficial towards reducing the risk of cancer.
Norman also lists 36 organ tissues in the body whose cells respond biologically to vitamin D. The list includes bone marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin, stomach and the uterus.
According to Norman, deficiency of vitamin D can impact all 36 organs. Already, vitamin D deficiency is associated with muscle strength decrease, high risk for falls, and increased risk for colorectal, prostate and breast and other major cancers.
The study’s recommendation for all adults is to have an average daily intake of at least 2000 IU. Levels under 10,000 IU/day are considered safe (more about toxicity here).
If you think you’re getting enough vitamin D just from the sun, the only way to know is to get a blood test for 25(OH) levels. A study showed that over half of residents of Miami, Florida, were deficient in vitamin D, and it gets worse as you go Northward. According to Dr. William Davis, a cardiologist who strongly recommends vitamin D supplements, even a tan doesn’t necessarily mean that you’re not vit D deficient, especially if you’re older (the skin loses its ability to generate vitamin D as you age).
Personally, I currently take 4,000 IU per day (in gelcaps like these, not dry tablets, because vitamin D is fat-soluble). If you decide to buy some, make sure to get D3 (cholecalciferol) and not the more expensive but less effective D2 (ergocalciferol).
About cost: 4,000 IU per day of Vitamin D costs me about $25.20 per year. There’s really no reason not to do it. And while you’re at it, also get a good multi-vitamin and some Omega 3 (I take around 1200 EPA + 600 DHA per day).