The blood level of 25 (OH) Vitamin D
nanograms/milliliter (ng/ml) and nanomoles/Liter (nmol/L)
1 ng/ml = 2.5 nmol.L
30 ng/ml = 75 nmol/L
Dose: International Units and micrograms
40 I.U. = 1 mcg
400 I.U. = 10 mcg
1000 I.U. = 25 mcg
50,000 I.U = 1250 mcg or 1.25 mg (milligram)