When to Supplement with Vitamin A

Most American get enough vitamin A from their diet. The USDA Continuing Survey to Food Intakes by Individuals in 1994-96 showed an average intake of 1,133 micrograms RE (Retinol Equivalent) of vitamin A for males aged 20 and older, and 982 micrograms RE for females aged 20 or older. The recommended intake for vitamin A for adult makes is 900 micrograms per day, and 700 micrograms for adult females.

Vitamin A deficiency is not a common problem in the United States. For that reason, vitamin A is not recommended for children in the United States. However, children, especially those in undeveloped countries, are at an increased risk because they have not yet built up their stores of vitamin A in the liver.

One of the earliest signs of too little vitamin A is night blindness - because of its role in vision. It is estimated that of the 500,000 children worldwide who become blind each year, as many as 70 percent do so because of a vitamin A deficiency. Symptoms of severe vitamin A deficiency can result in abnormal appearance and function of skin, lung, and intestinal tissues.

Although too little vitamin. A can pose a problem, too much can be just as devastating. Symptoms of extremely high dose of vitamin A can include nausea, vomiting, dizziness, blurred vision, muscular uncoordination, and increased cerebrospinal pressure. Chronic high intakes, on the other hand, can result in hair loss, liver damage, bone and muscle pain, headache, and increased blood lipid levels.