Your body rapidly absorbs vitamin A but only slowly clears it from your system, according to registered dietitian Mary Mitchell in "Nutrition Across the Life Span." Recommended daily allowances, or RDAs, define the amounts you need to provide adequate nutrition at various stages of your life, depending on your age, gender and physical condition. Some health conditions, including diarrhea, diseases of the eye, intestine, pancreas or stomach, infections and measles, may increase your need for vitamin A at a specific time, according to MayoClinic.com.
Infants and Children
Colostrum, special breast milk produced in the first three days after birth, contains twice as much vitamin A as mature milk. The extra vitamin A is responsible for the characteristic yellow color of colostrum. Mature milk contains 75 mcg of vitamin A per deciliter and is adequate to meet infant needs. The RDA for infants up to the age of 6 months is 400 mcg vitamin A per day, and for infants 6 months of age to 1 year, the RDA is 500 mcg of vitamin A per day. Infants who receive unfortified formula may need vitamin A supplements. Children ages 1 to 3 need 300 mcg of vitamin A per day, and children ages 4 to 8 need 400 mcg per day, according to the National Institutes of Health Office of Dietary Supplements.
Adolescents and Adults
Your teenager requires vitamin A for maintenance of epithelial cells and mucous membranes and for vision. Adolescents need vitamin A for this growth period. Children ages 9 to 13 need 600 mcg of vitamin A per day, according to registered dietitian Judith Brown in "Nutrition Through the Life Cycle." Adolescent males ages 14 to 18 and adult males 19 to 50 need 900 mcg per day. Adolescent females ages 14 to 18 and adult females ages 19 to 50 need 700 mcg of vitamin A per day.
Older Adults
Older adults are more likely to overdose on vitamin A than to become deficient in this nutrient. Older adults typically eat more than the recommended 900 mcg for males and 700 mcg for females over age 51, according to Brown. Absorption of vitamin A increases and clearance of vitamin A decreases with age. Older adults are more vulnerable to vitamin A toxicity and potential liver damage than younger individuals.
Pregnancy and Lactation
Excessive intake of retinal used to treat severe acne has been linked to birth defects, such as abnormalities of the central nervous system and craniofacial and cardiovascular defects, according to Mitchell. Avoid supplements containing high doses of vitamin A during pregnancy. Dietary intakes of carotenoids from plant-based foods have not been associated with this risk. Pregnant females age 18 and younger need 750 mcg of vitamin A per day and pregnant females age 19 and older need 770 mcg of vitamin A per day. Lactating females younger than 19 need 1,200 mcg of vitamin A per day, and lactating females 19 and older need 1,300 mcg of vitamin A per day, according Mitchell. The recommended amount for lactating women is higher than for non-lactating women to replace the vitamin A secreted in breast milk.
References
- "Nutrition Across the Life Span"; Mary Kay Mitchell, Ph.D., R.D.; 2003
- MayoClinic.com: Vitamin A (Oral Route, Intramuscular Route)
- Office of Dietary Supplements: Vitamin A and Carotenoids
- "Nutrition Through the Life Cycle, Third Edition"; Judith E. Brown, Ph.D., MPH, R.D.; 2008
- "Understanding Nutrition, Ninth Edition"; Eleanor Whitney, Ph.D., and Sharon Rolfes, M.S., R.D.; 2002
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