Multivitamins and mortality
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aarti Narayan, M.B.B.S [2]
Overview
Use of multivitamin supplements in the US has increased tremendously in past decade. According to the data from National Center for Health Statistics[1], over 50% of adults in the United States consume dietary supplements, with approximately 35% of adults taking multivitamin supplements. Annual multivitamin and dietary supplements sales total to $ 20 billion. Studies on multivitamin supplements have shown conflicting evidence on their effect on mortality, with some studies demonstrating an increase in risk of death, whereas others reporting no change in mortality.
Landmark Studies
Iowa Women Health Study[2]
- This was an observational study that assessed the long term effects of multivitamin supplements on mortality. It included 38,772 women with a mean age of 61.6 years at baseline.
- The study found increase in risk of total mortality in women on dietary and vitamin supplements, with highest increase in mortality seen in women on iron supplements. Calcium supplement intake was associated with a decrease in mortality.
- Limitations of the study include:
- Confounding factors: Smoking status, alcohol intake, BMI and lipid levels were not considered
- The study heavily relied on questionnaire
- Compliance of the women taking multivitamin and mineral supplements was not considered
- Although the multivitamin and dietary mineral intake patterns in these women were observed[3], the serum levels of vitamins and minerals were not studied to correlate the occurrence of death with intake of the supplements.
In contradiction to the above findings, another prospective longitudinal cohort study that assessed the long term effects of calcium on cardiovascular mortality demonstrated an increase in death rates from all causes and cardiovascular diseases in those on calcium supplements[4].
Other Studies
- A cohort study performed in Washington, assessed the long term effects of vitamin supplements on cardiovascular mortality using data collected from 77,719 residents of the Washington State aged 50 to 76 years by filling a self-administered questionnaire. The study demonstrated a small decrease in risk of cardiovascular mortality with vitamin E use and no effect on CVD mortality with use of vitamin C[5].
References
- ↑ Radimer K, Bindewald B, Hughes J, Ervin B, Swanson C, Picciano MF (2004). "Dietary supplement use by US adults: data from the National Health and Nutrition Examination Survey, 1999-2000". American Journal of Epidemiology. 160 (4): 339–49. doi:10.1093/aje/kwh207. PMID 15286019. Unknown parameter
|month=ignored (help) - ↑ Mursu J, Robien K, Harnack LJ, Park K, Jacobs DR (2011). "Dietary supplements and mortality rate in older women: the Iowa Women's Health Study". Archives of Internal Medicine. 171 (18): 1625–33. doi:10.1001/archinternmed.2011.445. PMID 21987192. Unknown parameter
|month=ignored (help) - ↑ Park K, Harnack L, Jacobs DR (2009). "Trends in dietary supplement use in a cohort of postmenopausal women from Iowa". American Journal of Epidemiology. 169 (7): 887–92. doi:10.1093/aje/kwn410. PMC 2727219. PMID 19208725. Unknown parameter
|month=ignored (help) - ↑ Michaëlsson K, Melhus H, Warensjö Lemming E, Wolk A, Byberg L (2013). "Long term calcium intake and rates of all cause and cardiovascular mortality: community based prospective longitudinal cohort study". BMJ (Clinical Research Ed.). 346: f228. PMC 3571949. PMID 23403980.
- ↑ Pocobelli G, Peters U, Kristal AR, White E (2009). "Use of supplements of multivitamins, vitamin C, and vitamin E in relation to mortality". American Journal of Epidemiology. 170 (4): 472–83. doi:10.1093/aje/kwp167. PMC 2727181. PMID 19596711. Unknown parameter
|month=ignored (help)