Vitamin A, also known as retinol or retinoic acid, is a nutrient with multiple functions in the human body. Your body obtains vitamin A from food but can also make it from beta-carotene. There is some research on the connection between lung cancer and vitamin A.
Vitamin A
Vitamin A is probably best known for its role in preventing vision problems. Deficiencies in this vitamin can cause night blindness or even complete loss of vision. Humans get vitamin A from animal sources such as meat, fish oils, egg yolks and dairy products. In addition, the body can make retinol, a type of vitamin A, from the beta-carotene found in fruits and vegetables such as carrots, broccoli, spinach, squash, peaches and apricots. Like many other vitamins, vitamin A also comes in supplement form.
Lung Cancer
The American Cancer Society estimates that over 220,000 cases of lung cancer will be diagnosed in the U.S. each year, and over 150,000 of those will die of the disease. Lung cancer is the leading cause of cancer death for both women and men. Men have an average lifetime chance of about 1 in 13 of developing lung cancer; for women it is 1 in 16. The risk is much higher for smokers of either gender.
Vitamin A and Lung Cancer
Data on the connection between vitamin A or beta-carotenes and lung cancer is mixed. One review of several studies published in the May 1990 journal "Nutrition Reviews" found that a high intake of fruits and vegetables that contained beta-carotene was associated with a decreased risk of lung cancer. However, there was little relation between vitamin A and lung cancer. A study in the September 2002 "Journal of Epidemiology" noted that the risk of lung cancer was lower when the intake of several vitamin A or beta carotene-related factors was high. The authors stated the findings suggest a diet high in fruits and vegetables, especially beta-carotene products, tomatoes and tomato-based products, might reduce the risk of lung cancer.
Vitamin A Supplements
According to the American Cancer Society, taking vitamin A supplements does not lower the risk of cancer in smokers; in fact, supplemental vitamin A actually increased the risk of death from lung cancer and heart disease. The ACS notes that the U.S. Institute of Medicine does not recommend use of vitamin A supplements by the general public. An extensive meta-analysis -- a review of multiple studies on a subject -- found there was a lack of evidence for the use of natural vitamin A substances in the treatment and prevention of lung cancers. This review, published in the "Public Library of Science One" in June 2011, did note that one compound, bexarotene, might have potential for a small subset of patients and should be studied further.
Considerations and Warnings
Lung cancer is a very serious disease and should not be self-managed. If you have questions or concerns, consult a health care professional.
References
- American Cancer Society; Lung Cancer (non-small cell) Overview; June 2011
- "Nutrition Reviews"; Vitamin A And Lung Cancer; W.C. Willett; May 1990
- "American Journal of Epidemiology"; Dietary Carotenoids, Serum Beta-Carotene, And Retinol And Risk Of Lung Cancer In The Alpha-Tocopherol, Beta-Carotene Cohort Study; C.N. Holick, et.al.;September 2002
- American Cancer Society; Treatment: Vitamin A and Beta Carotene; February 2010
- Public Library of Science One; Vitamin A and Retinoid Derivatives for Lung Cancer: A Systematic Review and Meta Analysis; Heidi Fritz, et.al.; June 2011
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