Vitamin A belongs to a group of vitamins called fat-soluble vitamins, which require the presence of dietary fat in order to be properly absorbed. Vitamin A ensures that your eyes remain healthy and allows you to see. Vitamin A also plays important roles in reproduction, immunity and cell differentiation. In order to keep your body healthy, it is important to consume the required amount of vitamin A every day.
Recommendations for vitamin A are based on age. Infants between 0 and 6 months require 400 mcg per day, whereas infants between 7 and 12 months need 500 mcg per day. Toddlers between 1 and 3 need 300 mcg every day. Children from the ages of 4 to 8 should consume 400 mcg per day, whereas children from 9 to 13 need 600 mcg per day. Adolescent boys between the ages 14 and 18 and adult men aged 19 and older require 900 mcg per day. Adolescent girls between the ages of 14 and 18 and adult women aged 19 and older need 700 mcg per day.
Women who are pregnant or breast-feeding have slightly increased vitamin A needs. Pregnant women aged 18 and younger should aim to consume 750 mcg per day, whereas pregnant women aged 19 and older require 770 mcg daily. Breast-feeding women aged 18 and younger should aim to consume 1,200 mcg of vitamin A every day, whereas breast-feeding women 19 and older require 1,300 mcg daily.
A wide variety of foods contain vitamin A. The best sources include cod liver oil, fortified breakfast cereals, eggs, butter and milk. Other good sources of vitamin A include sweet potatoes, pumpkin, carrot, cantaloupe, mangoes, spinach, broccoli, kale, collard greens and butternut squash.
If you do not regularly meet your vitamin A needs, you may develop a vitamin A deficiency. Because vitamin A is essential for healthy eyes, the first sign of a deficiency is often night blindness. Severe vitamin A deficiency can lead to a condition called xeropthalmia, which is characterized by extreme dryness of the cornea.
On the other hand, if you consume too much vitamin A, it can cause a vitamin A toxicity, called hypervitaminosis A. The development of hypervitaminosis A is usually gradual and results in dry itchy skin, loss of appetite, headache, bone pain and joint pain. The Food and Nutrition Board set the upper tolerable intake level, or UL, at 3,000 mcg per day for adults to avoid toxicity.