Daily vitamin requirements for women have been developed by the Institute of Medicine as part of the Dietary Reference Intakes, or DRIs. Both water soluble and fat soluble vitamins have either a Recommended Dietary Allowance or Adequate Intake associated with them. These standards are based on preventing deficiency symptoms.
Recommended Dietary Allowances
Registered dietitian Joanne Larson, on the website Ask the Dietitian, says that 98 percent of healthy Americans will get their nutrient needs met if their intake meets the scientifically-based RDAs. In actuality, there is also a safety allowance built in, so even if you only take in 67 percent of the RDA for any given nutrient an average person should get the minimum amount needed. Examples of vitamins with RDAs include thiamin, riboflavin, niacin, folate, A, B-6, B-12, C and E.
Adequate Intakes
Some vitamins lack a sufficient scientific basis to establish an RDA, so an Adequate Intake, or AI, is determined instead. An AI refers to the average daily amount of a vitamin that a group of healthy individuals consume. Both vitamins D and K have AIs associated with them, as do biotin and pantothenic acid.
Water Soluble Vitamins
Vitamin C and the B vitamins are considered water soluble because any excess ingested above needs is not stored by the body. B vitamins play essential roles in the utilization of energy from food. B vitamin RDAs for women include: thiamin, 1.1 mg; riboflavin, 1.1 mg; niacin, 14 mg; folate, 400 micrograms; vitamin B-6, 1.3 mg for women 19- to 50-years-old and 1.5 mg for women older than 50; vitamin B-12, 2.4 micrograms; and vitamin C, 45 mg. Vitamin C is an antioxidant and is essential for forming collagen, a protein found in tendons, ligaments, bones and teeth.
Water soluble vitamins with AIs for women include biotin, 30mcg; and pantothenic acid, 5mg. Pantothenic acid is involved in the synthesis of lipids, steroids, neurotransmitters and hemoglobin, whereas biotin is needed for fat synthesis.
Vitamin C is an antioxidant and is essential for forming collagen, a protein found in tendons, ligaments, bones and teeth. A woman's RDA for vitamin C is 45mg.
Fat Soluble Vitamins
Vitamins A, D, E and K are fat soluble vitamins. Toxicities of these can develop when excessive amounts are ingested, since the body stores any amount above needs. Vitamin A is important for vision, reproduction, growth and protein synthesis. The RDA for women is 700 micrograms. Vitamin D is unique because in addition to being a food component, it is also synthesized in the presence of sunlight. Its primary function is to maintain blood calcium and phosphorus levels to support bone growth. The AI for vitamin D is 600 IU for women up to age 70, and for those older, 800 IU. Vitamin E is an antioxidant that protects lipids from harmful oxidation and its RDA for women is 15 mg. Vitamin K plays a role in synthesizing blood clotting proteins. A woman's AI for vitamin K is 90 micrograms.
References
- Institute of Medicine Dietary Reference Intakes: Recommended Dietary Allowances and Adequate Intakes for Vitamins
- Institute of Medicine: DRIs for Calcium and Vitamin D
- Ask the Dietitian: Dietary Reference Intake (DRI) & Recommended Dietary Allowance (RDA); Joanne Larson MS RD LD
- University of Georgia: Dietary Reference Intakes
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