Cindy Geyer, M.D. (Lenox, Mass), Bruce Rothschild, M.D. (Lawrence, Kan)
I am writing in response to “Doubts Emerge About Widespread Use of Vitamin D Supplementation” (March 1, 2010, p. 1), particularly with regard to the possibility of increased arterial calcification. Although one study was cited as linking higher vitamin D levels in African Americans to increased calcification in the carotids and aorta, most of the article referred to a study looking at the effects of calcium supplementation, not vitamin D, on cardiovascular events. Since vitamin D deficiency is associated with an increase in PTH and an increase in osteoclast activity, it seems that supplementation of calcium alone (without adequate vitamin D) is more likely to cause the problem of soft tissue calcification. Perhaps the article should have also addressed doubts about the widely recommended use of 1,000 mg of supplemental calcium daily. I think the balance of the two is important. I now aim to have people get their vitamin D levels up at least to 30 ng/mL but try to meet most of their calcium needs through food. I then try to limit supplemental calcium for most people to no more than 500-750 mg daily.