If the vitamin D blood test was 30 ng/ml (75 nmol/L) and a 40 ng/ml (100 nmol/L) level was desired, 1,000 IU (25 mcg) of vitamin D per day over several months should be taken to achieve a normal ...

It’s a 25-hydroxy vitamin D blood test, levels of 20 to 50 nanograms/milliliters in a healthy person is satisfactory. Less than 12 ng/ml is a vitamin D deficiency.

Vitamin D3 is more effective at raising and maintaining the vitamin D blood test (again, D2 binds less tightly to the vitamin D receptors in the body; therefore, D2 does not circulate as long in ...