there are a plethora of articles on the potential benefits of vitamin d. as noted in many prior blogs, vitamin d receptors exist throughout the body. some vitamin d benefits are well-documented (bone, muscle, decrease in falls in elderly), some have small studies to support (improved response of TB to medications in those with adequate vitamin d levels, improved glucose tolerance), and many are epidemiologic studies (cancer — including prostate, breast, ovary; all-cause mortality; immunologic function and decrease in immunologic diseases — eg multiple sclerosis; heart disease,…) — for example, see doi: 10.1210/jc.2011-0385 for the endocrine society recommendations. the present article (see doi: 10.1097/gme.0000000000000188) supports a role in cholesterol profiles, from the Women’s Health Initiative calcium/vitamin D randomized trial. in brief,
–600 postmenopausal women (300 white, 200 African-American, 100 Latino) selected randomly from the Women’s Health Initiative CaD trial, randomized to elemental Ca 1,000 mg plus vit d 400IU/d vs placebo. 576 women with data to analyze: lipids assessed before and after the randomization. after 2 years:
–38% increase in 25OHD3 levels in those supplemented — 24.3 vs 18.2 ng/ml
–those on supplementation had 4.46 mg/dl decrease in LDL, nonsignif increase in HDL and nonsignif decrease in triglycerides (TG)
–those wtih higher 25OHD3 levels had higher HDL levels and lower LDL and TG. their figure discloses a linear relationship between increasing 25OHD3 levels on the range of 5-100 ng/ml and decreasing LDL as well as increasing HDL (dose-response curve), with a more complex relation with TG (decline begins around 15 ng/ml with linear decrease from that point to 100 ng/ml).
so, from this study the combo of ca/vit d helps lipids (though this is surrogate marker … really need to look at clinical events). unclear if vit d or calcium or combo is most beneficial. there are some data, for example, finding that calcium citrate by itself may have more beneficial lipid effect than calcium carbonate (used in this trial). one advantage of this study is that they looked at actual 25OHD3 levels achieved and lipid endpoints, instead of ecologic data based on general vitamin D supplementation and clinical results. and, in general, there was a clear, dose-response between the achieved vit D level and lipid markers. so, this study further supports either a strategy of checking 25OHD3 levels and supplementing when needed, or simply supplementing pretty much everyone in the northern climates….
geoff