Recommendation 14 Background

Vitamins are compounds necessary for the normal physiologic and metabolic functioning of the body.

This list includes carotenoids and vitamins. Carotenoids are pigments in foods responsible for many yellow, orange and red colors. Some carotenoids, including beta- and alpha-carotene, are precursors to vitamin A. Their food sources and relation to cancer risk are given below.

Vitamins and Carotenoids

Compound Food Sources
Beta-carotene Orange vegetables and fruits, dark green leafy vegetables, such as carrots, sweet potatoes, pumpkin, winter squash, cantaloupe, apricots, mangoes, kale, spinach, collard greens, chicory
Alpha-carotene Carrots, avocado, pumpkin
Lutein (a carotenoid) Spinach, kale, other greens
Lycopene (a carotenoid) Tomatoes and tomato products, watermelon, pink grapefruit, guava
Cryptoxanthin (a carotenoid) Mangoes, pawpaw, persimmon, red peppers, pumpkin, oranges and orange juice
Vitamin C Vegetables, tubers, fruits in general. Specifically, broccoli, cabbage, green leafy vegetables, peppers, tomatoes, pumpkin, potatoes, cassava (manioc), yams, citrus fruits, mangoes, papaya, banana, strawberries, melon.
Folate Dry legumes like lentils, beans, chickpeas, split peas; spinach and other green leafy vegetables, asparagus, artichoke, avocado, wheat germ, orange juice, pineapple, blackberries, tomato juice, breakfast cereals. fortified with folate.
Vitamin B12 Primarily foods of animal origin.
Vitamin E: alpha-tocoherol & gamma-tocopherol Vegetable oils like olive, canola, sunflower, safflower, corn, cottonseed, soybean and their margarines, shortening, mayonnaise and salad dressings. Also in whole grains, nuts, seeds and wheat germ. Alpha-tocopherol is present in animal foods.

Vitamins assessed in their relationship to cancer by the AICR/WCRF panel are the carotenoids, vitamin C, folate (also known as folic acid), vitamin B12, retinol (preformed vitamin A), and vitamin E. The following table summarizes and grades the current evidence for vitamins and cancer risk.

Vitamins and Cancer

Evidence Decreases risk No relationship
Probable Carotenoids: Lung

Vitamin C: Stomach

Possible Carotenoids: Esophagus, Stomach, Colon, Rectum, Breast, Cervix

Vitamin C: Mouth and Pharynx, Esophagus, Lung, Pancreas, Cervix

Vitamin E: Lung, Cervix

Retinol: Lung, Stomach, Breast, Cervix,

Vitamin C: Prostate

Vitamin E: Stomach, Breast

Folate: Cervix

Insufficient Carotenoids: Larynx, Ovary, Endometrium, Bladder

Vitamin C: Larynx, Colon, Rectum, Breast, Bladder

Retinol: Bladder

Vitamin E: Colon, Rectum

Folate & methionine: Colon, Rectum


Adapted from Food, Nutrition and the Prevention of Cancer: a Global Perspective, 1997

More on cancer risk in Recommendation 14/Minerals, Recommendation 14/Phytochemicals.

Practical recommendations in Recommendation 14 "How to"

For more details visit the web site for the Center for Alternative Medicine at

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EXTOXNET FAQS Diet and Cancer Homepage

Prepared 1998 by Bernadene Magnuson, Ph.D.
University of Idaho, Dept. of Food Science and Toxicology - EXTOXNET FAQ Team.