1.200 IU Vitamin D Won't Raise 25OH-D Levels Enough to See Beneficial Effects on Markers of Cardiovascular Health

In the course of the last weeks, I have refrained from posting each of the 1001 studies on vitamin D that appear in the myriad of medical magazines each month. It is simply too much, mostly very irrelevant information. A recent study by Maki et al. (Maki. 2011) is yet interesting insofar, as it provides some insight into the amounts of supplemental vitamin D one would probably need to see some cardiovascular benefits.

After supplementing the diets of their subjects with either a standard multi-vitamin or the multi-vitamin + 1,200IU of vitamin D for 8 weeks, the researcers measured serum 25-hydroxyvitamin D [25(OH)D] and high-density lipoprotein cholesterol (HDL-C) in subjects with high waist circumference and found:

There was a significant difference in mean change for 25(OH)D between the MVM and MVM+D treatment groups ( − 1.2 ± 2.5 nmol/l vs. 11.7 ± 3.0 nmol/l, respectively; P = 0.003). Vitamin D 1,200 IU/day did not increase 25(OH)D to a desirable level ( ≥ 75 nmol/l) in 61% of participants. There were no significant changes in cardiovascular disease risk markers. 

This is quite interesting, because even after all the fuss about vitamin D defiency that has even reached the mass media in the course of the last months, the general recommendation is not to take more than 1.000IU of vitamin D (sometimes even less) per day. For most people, this study seems to indicate, this is far too little to even get their vitamin D levels into the desirable ranges. Whether or not this would provide them with the beneficial results many scientists hope for, remains to be elucidated, though.