Though needs vary widely, the majority of men require 6000 units per day, women 5000 units per day. Only then do most men and women achieve what I’d define as desirable: 60-70 ng/ml 25-hydroxy vitamin D blood level.
I base this target level by extrapolating from several simple observations:
–In epidemiologic studies, a blood level of 52 ng/ml seems to be an eerily consistent value: >52 ng/ml and cancer of the colon, breast, and prostate become far less common; <52 ng/ml and cancers are far more likely. I don't know about you, but I'd like to have a little larger margin of safety than just achieving 52.1 ng/ml.
–Young people (not older people >40 years old, who have lost most of the capacity to activate vitamin D in the skin) who obtain several days to weeks of tropical sun typically have 25-hydroxy vitamin D blood levels of 80-100 ng/ml without adverse effect.
More recently, having achieved this target blood level in many people, I can tell you confidently that achieving this blood level of vitamin D achieves:
–Virtual elimination of “winter blues” and seasonal affective disorder in the great majority
–Dramatic increases in HDL cholesterol (though full effect can require a year to develop)
–Reduction in triglycerides
–Modest reduction in blood pressure
–Dramatic reduction in c-reactive protein (far greater than achieved with Crestor, JUPITER trial or no)
–Increased bone density (improved osteoporosis/osteopenia)
–Halting or reversal of aortic valve disease
Wow. As soon as I can reasonably manage, I’ll have Paul’s and my Vitamin D levels tested. I’ll report back the results, of course!