Studies have shown that there is a correlation between diet and disease, with a number of dietary elements associated with cancers e.g. aflatoxins, high salt intake, intake sugar and refined carbohydrates and high-fat diets. However, some dietary factors are thought to have protective factors for cancer prevention. Consumers seek vitamin and mineral supplements believing that these supplements will boost their immune system, slow ageing, prevent cancer and obtain other health benefits. There remains little evidence that modest chronic deficiencies in vitamins or minerals are associated with diseases.
Supplements and Health Benefits
One vitamin, which has been, associated with health benefits is vitamin D, which has been, linked to bone health. However, a large study of 1180 postmenopausal women who took daily supplements of either calcium with or without vitamin D or a placebo for four years showed a lower incidence of cancer, in those women who took both vitamin D and calcium supplements. Other studies have shown inconsistent results with vitamin D supplementation and cancer reduction such as in breast cancer. Folic acid has been with consistent results to showing that supplementation significantly reduces fetal abnormalities.
Adverse Effects of Supplements and Health
A number of studies are now indicating that vitamin and/or mineral supplements may have an adverse effect on people’s health. In a study, of 35,533 healthy men took either selenium, vitamin E, both or placebo for 7 years. The vitamin E group showed an increase in prostate cancer compared to the control groups. A further study reviewed the literature between 1966 and 2004 on supplementation with vitamin E and mortality rates. Miller et al. found that high-doses of vitamin E increased all cause mortality. However, this could be a reporting bias with studies with studies which did not show a beneficial effect not being published. Though a study, on men between the ages of 50-69 years who smoked at least 5 a day showed that vitamin E extended the lifespan by 2 years in the older age group.
A study, in 2011 in the Archives of Internal Medicine, showed that vitamin and mineral supplementation in healthy women is associated with an increase in risk of mortality and this was particularly identified with iron supplementation. However, a further study, in 2011 published in the American Journal of Epidemiology, on 182,099 men and women who were followed for 11 years showed that there was no clear increase or decrease in mortality from all causes, in the group that took supplements.
The benefits of vitamin and mineral supplementation in healthy people remains uncertain.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
Sources
- Age Ageing. Vitamin E may affect the life expectancy of men, depending on dietary vitamin C intake and smoking.Hemilä H, Kaprio J. 2011: 40
- American Journal of Clinical Nutrition. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Lappe JM, et al. 2007:85
- American Journal of Epidemiology. Multivitamin use and the risk of mortality and cancer incidence: the multiethnic cohort study. Park SY, et al. 2011: 173
- Annals of Internal Medicine. Meta-analysis: high dosage vitamin E supplementation may increase all cause mortality. Miller ER, et al. 2005: 142
- Archives of Internal Medicine. Dietary supplements and mortality rate n older women: the Iowa women’s health study. Mursu J. et al. 2011: 171
- BMC Public Health. Th effect of folic acid, protein energy and multiple micronutrient supplements in pregnancy on stillbirths.Imdad A, et al. 2011: 13
- International Journal of General Medicine. How to reduce your cancer risk: mechanisms and myths. Nahleh Z, et al. 2011: 4
- JAMA. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). Klein EA, et al. 2011: 306
Kerstin Rolfe - Kerstin Rolfe is a research scientist who writes in her free time because she loves writing. She was awarded a PhD from the University of ...
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