RDA Values for Vitamins

The recommended dietary allowance, or RDA, represents the average amount of a specific nutrient that meets the needs of 97 to 98 percent of people in a specific age and gender group, writes nutrition expert Joan Salge Blake in "Nutrition and You." The RDA values for vitamins are set by the Food and Nutrition Board, which is a subgroup of the Institute of Medicine.

Vitamin D

The RDA for vitamin D ranges from 5 to 15 mcg for adults. The specific amount of vitamin D that you need in your diet depends on your amount of exposure to sunlight. This is because your skin can synthesize some vitamin D with exposure to the ultraviolet rays of the sun.

Vitamin A

Vitamin A is measured in two ways: retinol activity equivalents, or RAE, and international units, or IU. Because retinol is the most active form of vitamin A, Blake notes that RAE is the preferred way to measure vitamin A intake. The RDA for vitamin A is 700 mcg RAE for adult women and 900 mcg RAE for adult men. One mcg RAE is equivalent to 3.3 IU.

Vitamin E

Both female and male adults require 15 mcg of vitamin E per day. There are eight different forms of vitamin E, but the only form that is active in the human body is called alpha-tocopherol. Because of this, your vitamin E intake should be in this form.

Vitamin K

The bacteria in your digestive tract are able to synthesize a small amount of vitamin K, although it's unclear exactly how much. Because of this, the RDA for vitamin K applies to dietary intake only. Adult women should consume 90 mcg of vitamin K per day, while adult men require 120 mcg daily.

Vitamin C

The RDA for vitamin C for women is 75 mg per day, whereas the RDA for men is 90 mg daily. Cigarette smoke accelerates the breakdown of vitamin C in the body. Because of this, smokers require 35 mg more vitamin C per day than non-smokers. A female smoker should aim to consume 110 mg of vitamin C, while a male smoker should aim for 125 mg daily.

B Vitamins

Eight different vitamins make up the category of vitamins known as the B vitamins. These vitamins include thiamin, riboflavin, niacin, vitamin B6, biotin, pantothenic acid, folate and vitamin B12. Each B vitamin has its own RDA.

Adult women should consume 1.1 mg of thiamin, whereas adult men should consume 1.2 mg. The RDA for riboflavin is also 1.1 mg for women and increases slightly to 1.3 mg for men. Female adults need 14 mg of niacin per day, while adult men need 16 mg. The RDA for vitamin B6 is given in ranges. Women should consume between 1.3 and 1.5 mg, and men should consume between 1.5 and 1.7 mg. The RDAs for biotin, pantothenic acid, folate and vitamin B12 are 30 mcg, 5 mg, 400 mcg and 2.4 mcg, respectively.