"Micronutrient needs in adults differ slightly according to sex. Young men and women who are very athletic and perspire a great deal also require extra sodium, potassium, and magnesium. Males require more of vitamins C and K, along with thiamine, riboflavin, and niacin. Females require extra iron due to menstruation. Therefore, it can be beneficial for some young adults to follow a daily multivitamin regimen to help meet nutrient needs. But as always, it is important to remember “food first, supplements second.” Micronutrient recommendations for adult males and females are as follows: vitamin A, 900.0 mcg for males and 700.0 mcg for females; vitamin B6, 1.3 mg for both; vitamin B12, 2.4 mcg for both; vitamin C, 90.0 mg for males and 75.0 mg for females; vitamin D, 5.0 mcg for both; vitamin E, 15.0 mg for both; vitamin K, 120.0 mcg for males and 90.0 mcg for females; calcium, 1,000.0 mg for both; folate, 400.0 mcg for both; iron, 8.0 mg for males and 18.0 mg for females; magnesium, 400.0 mg for males and 310.0 mg for females; niacin, 16.0 mg for males and 14.0 mg for females; phosphorus, 700.0 mg for both; riboflavin, 1.3 mg for males and 1.1 mg for females; selenium, 55.0 for both; thiamin, 1.2 mg for males and 1.1 mg for females; and zinc, 11.0 mg for males and 8.0 mg for females."