Originally published on positiveimpactmagazine.com on August 11, 2011
By: Dr. Joel Fuhrman, MD
Maintaining adequate levels of essential vitamins and minerals is crucial for good health. Suboptimal intake of some vitamins is a risk factor for chronic diseases and common in the general population, especially the elderly.  In contrast, micronutrient adequacy has the potential to extend lifespan – recent research has found that multivitamin use is associated with longer telomere length, which is an indicator of a slower rate of aging. 
Eat your veggies!
Of course, a healthful diet based on whole plant foods is our best protection against chronic disease. In addition to vitamins and minerals, a diet of colorful natural plant foods provides us with thousands of beneficial phytochemicals. But there are some nutrients that are lacking even in an ideal diet, and deficiencies can undermine your health. Also, we cannot be sure that we are getting the precise optimal amounts of vitamins and minerals every day from our diet – especially since absorption efficiency and utilization of nutrients varies from person to person. A high quality multivitamin can fill these gaps, ensuring that we get adequate amounts of essential micronutrients.
Certain vitamins and minerals are often lacking even in a healthy diet:
• Vitamin B12
Vitamin B12 is required for important biological functions like red blood cell production, nervous system function, and DNA synthesis. Deficiency in B12 can cause a variety of health problems including elevated homocysteine (a cardiovascular risk factor), anemia, depression, confusion, fatigue, digestive issues, and nerve damage.  Insufficient B12 levels are also associated with increased risk of Alzheimer’s disease. 
Vitamin B12 is unique in that it is made only by mircoorganisms. Because our produce is washed and often transported far before we eat it (soil contains B12-producing microorganisms), most of us are unable to get sufficient B12 from plant foods alone. B12 deficiency is common, especially in vegans who don’t supplement and in the elderly – our ability to absorb B12 decreases with age, and about 20% of adults over the age of 60 are either insufficient or deficient in vitamin B12.  Supplementation with vitamin B12 is likely important for most people, and absolutely required for most vegans to achieve sufficient B12 levels. 
Iodine is required by the body to make thyroid hormones. A recent study of vegans estimated that only about 40% of the daily requirement for iodine was commonly met on a vegetarian or vegan diet.  Another study concluded that 80% of vegans, 25% of vegetarians, and 9% of conventional eaters are iodine-deficient.  Most plant foods are low in iodine due to soil depletion. Kelp, a sea vegetable, is a good source of iodine, but is not commonly eaten on a regular basis. The chief source of iodine in the typical American diet is iodized salt. Since salt should be avoided for good health, it is important to supplement with iodine to maintain adequacy.
Zinc is essential for immune function, growth, and reproduction, and supports hundreds of chemical reactions. Zinc is abundant whole plant foods, but is not readily absorbed. Beans, whole grains, nuts, and seeds contain zinc, but also contain substances that inhibit zinc absorption.  A recent study of vegetarians found a high prevalence of zinc deficiency, and zinc requirements for those on a completely plant-based diet are estimated to be about 50% higher than the U.S. RDI. [10,11] Zinc is especially important for men, because it is concentrated in the prostate and promotes death of cancer cells, possibly by suppressing the activity of inflammatory molecules. Long-term zinc supplementation is associated with reduced risk of advanced prostate cancer. 
Multivitamins must be chosen wisely
While most people can certainly benefit from a multivitamin, it is important to choose the right one. It is important to avoid vitamin and mineral deficiencies, but it is just as important to avoid consuming excessively high levels of certain nutrients. Many nutrients can be toxic or otherwise harmful in supplement form or in large doses.
My Gentle Care Formula is designed to complement a healthy diet, and the most current nutrition research is used to determine what it does and does not contain. The levels of vitamins and minerals in my Gentle Care Formula are optimized to provide enough of each nutrient while not running the risk of excessive intake, and to exclude potentially harmful ingredients, especially folic acid and Vitamin A.
References 1. Fletcher RH. Fairfield KM. Vitamins for Chronic Disease Prevention in Adults: Clinical Applications; JAMA; 2002; 287(3127-129 .2. Xu Q, Parks CG, DeRoo LA, et al. Multivitamin use and telomere length in women. Am J Clin Nutr. 2009 Jun;89(6):1857-63. 3. Office of Dietary Supplements, National Institutes of Health. Dietary Supplement Fact Sheet: Vitamin B12 [http://ods.od.nih.gov/factsheets/VitaminB12/] 4. Hooshmand B, Solomon A, Kareholt I, et al: Homocysteine and holotranscobalamin and the risk of Alzheimer disease: a longitudinal study. Neurology 2010;75:1408-1414. 5. Allen LH: How common is vitamin B-12 deficiency? Am J Clin Nutr 2009;89:693S-696S. 6. Bor MV, von Castel-Roberts KM, Kauwell GP, et al: Daily intake of 4 to 7 microg dietary vitamin B-12 is associated with steady concentrations of vitamin B-12-related biomarkers in a healthy young population. Am J Clin Nutr 2010;91:571-577. 7. Waldmann A, Koschizke JW, Leitzmann C, Hahn A. Dietary intakes and lifestyle factors of a vegan population in Germany: results from the German Vegan Study. European Journal of Clinical Nutrition (2003) 57, 947–955. 8. Krajcovicová-Kudlácková M, Bucková K, Klimes I, Seboková E.. Iodine deficiency in vegetarians and vegans. Ann Nutr Metab. 2003;47(5):183-5. 9. Hunt JR. Bioavailability of iron, zinc, and other trace minerals from vegetarian diets. Am J Clin Nutr 2003;78(suppl):633S–9S. 10. de Bortoli MC, Cozzolino SM. Zinc and selenium nutritional status in vegetarians. Biol Trace Elem Res. 2009 Mar;127(3):228-33. Epub 2008 Oct 25. 11. Frassinetti S, Bronzetti G, Caltavuturo L, et al. The role of zinc in life: a review. J Environ Pathol Toxicol Oncol. 2006;25(3):597-610. 12. Gonzalez A, Peters U, Lampe JW, White E. Zinc intake from supplements and diet and prostate cancer. Nutr Cancer. 2009;61(2):206-15.
Disclaimer: This article was written for educational purposes only. It is not intended to treat, diagnose, prescribe or heal any health condition or to replace standard medical treatment or advice.