Friday, March 09, 2007

Multiple Vitamins - Waste or Wise?

Multiple Vitamins - Waste or Wise? The information in this presentation is for educational purposes only. It is not intended to serve as a replacement for the advice of a medical professional. Amid the current confusion about whether or not to take multivitamins, here are some facts you should consider: There are widespread nutrient deficiencies in America: According to dietary data from the National Health and Nutrition Examination Survey 1999-2000, ninety percent or more of the adults studied had their usual intakes below the current Estimated Average Requirement. 9-11 A report published in the medical journal JAMA made this strong statement: “Most people do not consume an optimal amount of all vitamins by diet alone. Pending strong evidence of effectiveness from randomized trials, it appears prudent for all adults to take vitamin supplements.” 2 There is strong evidence that multivitamins may improve immune functions in adults: A so-called “gold standard” randomized, double-blind, placebo-controlled trial looked at adults age 45+ during a one-year study, with results of diabetic and non-diabetic subjects reported separately. 1 73% of those receiving the placebo reported getting infections over the year versus 43% of those taking multivitamins, a 30% difference. Infection-related absenteeism was also found to be much higher in the placebo group (57%) than in the treatment group (21%). But the most striking results were found among the diabetic subjects. A whopping 93% of diabetics receiving the placebo reported getting infections versus only 17% of those taking vitamins, an amazing 76% difference! In other words, the diabetics that did not take multivitamins were over five times as likely to report infections as those in the group that did take the vitamins. Multivitamins reduce birth defects: A meta-analysis of published studies reviewing women’s use of prenatal multivitamins was published by the Journal of Obstetrics and Gynaecology of Canada (JOGC). Researchers found that taking prenatal multivitamins may reduce the risk of a wide range of serious birth defects, including: cardiovascular and limb defects, cleft palate and oral cleft, congenital hydrocephalus, and urinary tract anomalies. Their conclusion was that, “Maternal consumption of folic acid-containing prenatal multivitamins is associated with decreased risk for several congenital anomalies, not only neural tube defects. These data have major public health implications, because until now fortification of only folic acid has been encouraged. This approach should be reconsidered.” 3 The data indicated that the possible benefits to infants of their mothers taking prenatal multivitamins went far beyond the well-known prevention of neural tube defects in the children. That known benefit has already led to widespread fortification of folic acid in processed foods, especially refined flour. Multivitamins protect pregnant women and their fetuses: Another possible benefit of multivitamin use is to prevent potentially fatal complications in pregnant women. This finding was reported by researchers at the University of Pittsburgh: “Women who are considering becoming pregnant may significantly reduce their risk of developing a common life-threatening complication called pre-eclampsia by taking a multivitamin supplement regularly three months before conception and during the first trimester of pregnancy.” 8 Multivitamins reduce infertility: Harvard scientists found that women who took multivitamins at least six times a week were over 40% less likely to have fertility problems linked to ovulation than other women. Dr Jorge Chavarro, from the Harvard School of Public Health, presented his findings to delegates at the American Society for Reproductive Medicine conference in New Orleans in October, 2006. 4 Multivitamins and chronic conditions: Another scientific review published in JAMA noted that, “Although the clinical syndromes of vitamin deficiencies are unusual in Western societies, suboptimal vitamin status is not. Because suboptimal vitamin status is associated with many chronic diseases, including cardiovascular disease, cancer, and osteoporosis, it is important for physicians to identify patients with poor nutrition or other reasons for increased vitamin needs. The science of vitamin supplementation for chronic disease prevention is not well developed, and much of the evidence comes from observational studies.” 5 The report concluded, “Some groups of patients are at higher risk for vitamin deficiency and suboptimal vitamin status. Many physicians may be unaware of common food sources of vitamins or unsure which vitamins they should recommend for their patients. Vitamin excess is possible with supplementation, particularly for fat-soluble vitamins. Inadequate intake of several vitamins has been linked to chronic diseases, including coronary heart disease, cancer, and osteoporosis.” Multivitamins may reduce childhood tumors: In a case-control study of brain tumors and the mothers’ use of vitamin and mineral supplements early in pregnancy, the researchers confirmed earlier research indicating that mothers taking multivitamins had a reduced risk of their child developing brain tumors. “The results of the study add to the evidence of a protective role for multivitamins, suggest a possible role for micronutrients early in pregnancy...” 6 Vitamin-Mineral Deficiencies are Theoretically Linked to Increased Cancer Risks: Researchers writing in the scientific journal Nature Reviews Cancer have stated, “Diet is estimated to contribute to about one-third of preventable cancers -- about the same amount as smoking. Inadequate intake of essential vitamins and minerals might explain the epidemiological findings that people who eat only small amounts of fruits and vegetables have an increased risk of developing cancer. Recent experimental evidence indicates that vitamin and mineral deficiencies can lead to DNA damage. Optimizing vitamin and mineral intake by encouraging dietary change, multivitamin and mineral supplements, and fortifying foods might therefore prevent cancer and other chronic diseases.” 7 There is a wide range of published research on multivitamins and I have presented only a sampling to you today. I hope that this information intrigues you as to the potential benefits of the vitamins and minerals found in multivitamins, and the fact that some respected health authorities advocate that most Americans take a good multivitamin. Copyright 2007 Neil E. Levin REFERENCES: Barringer TA, et al. Effect of a multivitamin and mineral supplement on infection and quality of life. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 2003 Mar 4;138(5):365-71. PMID: 12614088 Fairfield KM, Fletcher RH. Vitamins for chronic disease prevention in adults: scientific review. JAMA. 2002 Jun 19;287(23):3116-26. Review. Erratum in: JAMA 2002 Oct 9;288(14):1720. PMID: 12069675 Goh YI, et al. Prenatal multivitamin supplementation and rates of congenital anomalies: a meta-analysis. J Obstet Gynaecol Can. 2006 Aug;28(8):680-9. PMID: 17022907 Chavarro, J. (Harvard School of Public Health) American Society for Reproductive Medicine conference. New Orleans, LA. October 2006. Fairfield KM, Fletcher RH. Vitamins for chronic disease prevention in adults: scientific review. JAMA. 2002 Jun 19;287(23):3116-26. Review. Erratum in: JAMA 2002 Oct 9;288(14):1720. PMID: 12069675 Bunin GR, et al. Maternal supplement, micronutrient, and cured meat intake during pregnancy and risk of medulloblastoma during childhood: a children's oncology group study. Cancer Epidemiol Biomarkers Prev. 2006 Sep;15(9):1660-7. PMID: 16985028 Ames BN, Wakimoto P. Are vitamin and mineral deficiencies a major cancer risk? Nat Rev Cancer. 2002 Sep;2(9):694-704. Bodnar LM, et al. Periconceptional multivitamin use reduces the risk of preeclampsia. Am J Epidemiol. 2006 Sep 1;164(5):470-7. Epub 2006 Jun 13. PMID: 16772374 Dial S, Eitenmiller RR. 1995. Tocopherols and tocotrienols in key foods in the U.S. diet. In: Ong ASH, Niki E, Packer L, eds. Nutrition, Lipids, Health, and Disease. Champaign, IL: AOCS Press. Pp. 327–342. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000). Institute of Medicine, NIH Ahuja JK, et al. Current status of vitamin E nutriture. Ann N Y Acad Sci. 2004 Dec;1031:387-90. PMID: 15753177

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