Also known as: retinol, vitamin A1, and vitamin A2.
Potential uses: Vitamin A is used to help improve immune system function. It's also used to promote healing and eye health.
Usual dose: 700 micrograms (2,310 international units) per day is the recommended daily allowance for adult women. Eating 5 or more servings of colorful fruits and vegetables per day will help you to get enough vitamin A. Dairy products and some cereals are fortified with vitamin A.
Are there any risks? Too much vitamin A may cause nausea, vomiting, and headache. High doses of vitamin A may also increase the risk for osteoporosis.
What does the research show? Studies of vitamin A show no effect on breast cancer risk.