Posted 1/14/2021 11:06 AM (GMT -7)
There is no substitute for getting your blood levels of vit D measured. Vitamin D3 is the natural version. We UCers are likely to be deficient since we may have problems with absorption. (Actually I think most people are deficient).
Optimal values are between 40 and 60 ng/ml. Measurements near 100 ng/dl are technically safe but that leaves little margin for error since vitamin D can be overdosed. I need to take about 5,000 IU of D3 each day to maintain my blood levels within the optimum range.
5,000 IU may seem excessive but consider one full day at the beach, without sunscreen (if you can avoid getting burned to a crisp), will provide about 25,000 IU. I play a lot of golf outdoors and go to the beach often and still need to supplement.