Vitamin A is available from many sources in diet, not just animals

November 13, 2011

UNIVERSITY PARK, Pa. -- Recent surveys show that a growing number of people are deciding to abstain from consuming animal products. But if they're not careful, that decision can result in deficiencies of certain nutrients needed for optimum health, according to a nutrition expert in Penn State's College of Agricultural Sciences.

Vitamin A is one of the essential nutrients needed by the human body that is found in animal products, noted J. Lynne Brown, professor of food science. But vitamin A also can be obtained by eating plant foods in a balanced diet, she pointed out.

"Vitamin A in the active form of retinol is provided by animal foods such as liver, fish, liver oil, whole milk, cheese, whole eggs and fortified food products such as margarine or butter," she said.

"Vitamin A in the provitamin carotenoid form also is obtainable by eating colorful fruits and vegetables, such as tomatoes, carrots, spinach, kale, sweet potatoes, cantaloupe, apricots, papayas, mangoes, peaches and sweet peppers."

However, Brown cautioned, only 20-50 percent of carotenoids found in plants are absorbed by the human body, so vegans and vegetarians should eat more than five servings a day of these fruits and vegetables.

"Efficient absorption also requires a portion of fat in your meal," she said.

With a balanced diet, vitamin A supplements often are unnecessary, and Brown explained that too much vitamin A in the body is not safe. "You always should talk to your health-care provider before taking vitamin supplements to avoid vitamin-medication interactions and over-supplementation," she said.

Vitamin A deficiency is more common in developing countries, but Brown said alcohol intake also reduces vitamin A stores. "People consuming excessive alcohol need to include good sources of vitamin A in their diets," she advised, adding that supplements are not recommended in this case because the high doses delivered by supplements can poison the liver. Food sources of vitamin A are safer.

Penn State's College of Agricultural Sciences offers publications with pertinent information about vitamin supplementation for health. These fact sheets, authored by Brown, detail the health benefits and risks of vitamin A, D and E supplements. They are available on the Web at

Single copies of each fact sheet can be obtained free of charge by Pennsylvania residents through county Penn State Extension offices, or by contacting the College of Agricultural Sciences Publications Distribution Center at 814-865-6713 or by email at For cost information on out-of-state or bulk orders, contact the Publications Distribution Center.

  • A Penn State fact sheet offers advice about getting vitamin A in one's diet.

    IMAGE: Penn State

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Last Updated November 17, 2011