Question: is iu same as mcg?
Answer: Vitamin A 1 IU is the biological equivalent of 0.3 micrograms (mcg) retinol, or of 0.6 micrograms beta-carotene; 1 nanogram (ng)/ml = 3.5 nanomol (nmol)/l. 1 IU is 50 micrograms (mcg) L-ascorbic acid; 1 ng/ml = 5.5 nmol/l.