AJCN Jan, 2007 Supplement: Multivitamin/Mineral Supplements and Chronic Disease Prevention: State-of-the-Science Conference: Multivitamin/Mineral Supplements and Chronic Disease Prevention
Table of Contents is here. Introduction to the conference is here.
Executive Summary http://www.ajcn.org/cgi/content/full/85/1/265S
Below I summarize in my own words or through direct quotations what I found to be useful statements.
” The purpose of this conference—Multivitamin/Mineral Supplements and Chronic Disease Prevention—was to evaluate the state-of-the-science regarding several key questions about the role of multivitamin and multimineral supplements (MVMs) in health promotion and in reducing the risk of chronic diseases such as cancer and cardiovascular disease, among others. ” “Current estimates of the $20 billion annual investment in supplements by American consumers suggest that roughly one-third of that is spent on vitamins and minerals—approximately $7 billion in 2005 (1). Of this amount, it is estimated that half or more is spent on MVM combinations, so that this segment of the market accounted for about $3.5 billion in sales in the United States last year.”
Of 11,324 articles published from 1966 through February 2006 about multivitamin use and benefits, only 63 were considered suitable to decide whether multivitamins are useful. Reviewing those studies, there were no clear benefits to multivitamin use.
“Most multivitamin/mineral supplements contain at least 10 vitamins or minerals with a wide range of doses. ”
[Nutrition-related diseases and most important vitamins]” Chronic disease is estimated to account for 35 million deaths worldwide. Cardiovascular disease and cancer comprise a major proportion of chronic diseases in both developed and developing countries. Other than cardiovascular disease and cancer, obesity-related diseases such as type 2 diabetes, end-stage renal disease, and osteoarthritis are also becoming significant public health problems. Many of these chronic diseases share common risk factors and underlying pathologic mechanisms that may be modified by nutrients. Examples include reduction of oxidative damage by antioxidants, DNA methylation regulated by folate and B vitamins, bone metabolism regulated by vitamin D and calcium, and cell differentiation, proliferation, and growth regulated by retinol, calcium, and vitamin D.”“The United States Food and Nutrition Board has established the tolerable upper intake levels (ULs) for several nutrients. By definition, a UL is the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects to almost all individuals in the general population. ”
“The SU.VI.MAX study in a French population documented a 31 percent reduction in overall cancer risk by use of vitamin C, vitamin E, ß-carotene, selenium, and zinc at doses 1–2 times the RDAs for 8 years in men but not in women. A 12 percent reduction in prostate cancer risk, particularly a 48 percent risk reduction in those with normal prostate specific antigen levels at baseline, was found in men receiving active supplements compared to men receiving placebo. ”
“In the Age-Related Eye Disease Study (AREDS), high-dose zinc (10 times the RDA) alone or combined with antioxidants (5 to 15 times the RDAs) had beneficial effects on age-related macular degeneration only in those with intermediate age-related macular degeneration in one or both eyes, or those with advanced age-related macular degeneration in one eye.”
“Daily supplementation with ß-carotene of 20 mg, 30 mg or 50 mg was not protective against malignancies, cardiovascular disease outcomes, diabetes mellitus, cataract or age-related maculopathy. Supplementation with ß-carotene with or without vitamin A increased the incidence of lung cancer in persons with asbestos exposure or in smokers”
Vitamin E supplements (synthetic -tocopherol 50 mg or 300 IU per day, natural vitamin E 500 IU, or natural source vitamin E, 600 IU per day) provided for a 32 percent reduction in prostate cancer incidence, a 41 percent reduction in the prostate cancer mortality, and a 22 percent reduction in colorectal cancer in smokers in the ATBC study, and decreased cardiovascular deaths (primarily sudden death) in the WHS participants, particularly in those aged 65 years or older.
higher intake of calcium (an average of 1150 mg per day) than the general population (761 mg per day) and vitamin D3 (700–800 IU/day) decreased hip fractures.
Multivitamin-multimineral supplements: who uses them? 52% of adults reported taking a dietary supplement in the past month, and 35% reported regular use of a multivitamin-multimineral (MVMM) product.
SAFETY ” A study commissioned by the Food and Drug Administration (FDA) estimated that the FDA is notified of <1% of all adverse events associated with dietary supplements. Among the factors that may contribute to underreporting are that many consumers presume supplements to be safe, use these products without the supervision of a health care professional, and may be unaware that the FDA regulates them.”
In particular, it was found that many people are obtaining too much iron, zinc, vitamin A, and niacin by taking multivitamins that are not formulated wisely.
Lots of fascinating stuff which I invite you to peruse from the Table of Contents for the Symposium.
Please also see Nutrition Investigator comments on multivitamins