Too much vitamin A may lead to bone fractures. A 30-year study reported in the New England Journal of Medicine found men older than 49 with the highest blood levels of fat-soluble vitamin A (retinol) were at a high risk for fractures. But nutritionists caution people not to avoid vitamin A, because it's needed for optimum health. The Institute of Medicine recommends that women get 2,333 international units (IU) of vitamin A daily; men should get 3,000 IU. Good sources of vitamin A include liver, eggs, fortified milk (preferably skim or low fat), carrots, sweet potatoes, cantaloupe, kale and spinach.