Vitamin A, a fat-soluble vitamin, supports cell growth and differentiation. It helps keep your eyes healthy and plays an active role in the development of an embryo and fetus. It is essential in keeping skin and mucous membranes that line the mouth, sinuses and nose in a healthy condition. Vitamin A also supports bone formation, growth, reproduction and immune system function. Good dietary sources of vitamin A include dairy products, cantaloupe, mangoes, sweet potatoes, dark-green leafy vegetables, carrots and pumpkin. Consuming the required amount of vitamin A daily helps maintain overall health.
Vitamin A Pediatric Dosage
Infants up to 6 months need 400 micrograms of vitamin A per day, while infants between ages 7 months and 12 months require 500 micrograms per day. For children aged 1 to 2 years, the recommended daily allowance, or RDA, for vitamin A is 300 micrograms. Children from the ages of 4 to 8 should consume 400 micrograms each day, whereas children from 9 to 13 need 600 micrograms daily. The RDA for boys aged 14 years to 18 years is 900 micrograms, whereas for girls in the same age group, the RDA is 700 micrograms.
Vitamin A Requirements for Adults
Adult men aged 19 and older should consume 900 micrograms of vitamin A per day. The daily requirement of the vitamin for adult women aged 19 and older is 700 micrograms.
Women With Special Needs
Women who are pregnant or breastfeeding need extra amounts of vitamin A. Pregnant women aged 14 to 18 should aim to get about 750 micrograms per day, while pregnant women aged 19 and older require 770 micrograms every day. Breastfeeding women between 14 to 18 should aim to consume 1,200 micrograms of vitamin A per day, whereas breastfeeding women 19 and older should shoot for a daily 1,300 micrograms of this nutrient.
Failing to meet your daily vitamin A requirements may result in a deficiency. Vitamin A deficiency leads to night blindness, or impaired dark adaptation. More seriously, it can cause xerophthalmia, or dry eye, which is distinguished by changes in the corneal cells that finally lead to blindness, corneal ulcers and scarring. On the other hand, vitamin A is toxic and can cause liver failure and death when taken in large amounts. Symptoms of vitamin A toxicity include dry skin and lips, headache, fatigue, hair loss, nausea, irritated eyes and muscle and joint pain. You should monitor all vitamin formulas you are taking as many contain vitamin A. Taking multiple formulas can easily add up to high amounts. For adult men and women, the tolerable upper limit for vitamin A is 3,000 micrograms per day. Do not take more than the recommended daily allowance without first consulting your doctor, cautions the University of Maryland Medical Center.