Why Do People Take Multivitamins? Another Survey Says: To Fill Nutrient Gaps
I take a multivitamin. I first started taking them at university, a time when my diet lead a lot to be desired. It was part of my routine when I felt a bit run down: go to bed early and take a multivitamin. Maybe that cold was coming on because my normal diet consisted of instant noodles, toast and butter chicken, with nary a vegetable in sight? Fast forward a number of years and even though my diet has improved, I take them a few times a week to make sure that I am getting enough of everything. This is a sentiment reflected by the majority of multivitamin and other dietary supplement users, according to Dickinson, McKay and Wong. They surveyed a representative sample of 2159 adults living in the US about their perceptions about dietary supplements. These participants were not necessarily dietary supplement users themselves: only half of US adults use a supplement within a given month according to Bailey and co-workers. Another research group, led by Dickinson, found that the majority of supplement users use a supplement regularly, and 70% of the time this is a multivitamin.
The survey asked people their opinion on dietary supplements and their role in filling dietary gaps. Over 80% of the participants agreed with statements that supplements can be useful to meet nutrient requirements that cannot be met by food alone and can be considered part of a healthy diet. In addition, over 80% also agreed that they should not be used to replace a healthy diet and that the use of high dose supplements should occur with the knowledge of a physician. In addition, 75% felt that multivitamins are not meant to cure diseases, and 67% felt that they were not medicine. These results agree in with attitudes presented by Bailey, who found almost 80% of supplement users did so to improve or maintain health, and 22% to supplement the diet. 15% take a dietary supplement for heart health, and other chronic diseases are not specifically mentioned.
This is in contrast to the opinion of Guallar and co-workers, who caution against the use of multivitamins as they do not prevent chronic disease or death. Despite the fact that the largest and longest randomized clinical trial of (what people consider to be) multivitamins showed a modest yet significant reduction in cancer incidence (Gaziano), most people take multivitamins for general health or to fill a perceived gap in the diet. As a nutrition scientist, I am aware more than most people of nutrient deficiencies, their prevalence and symptoms. I try to eat a healthy diet. But there are so many nutrients and it can be difficult to work out whether I am getting enough of them. Like everyone else, I take multivitamins to ensure that I meet the minimum nutrient intakes.
Annette Dickinson, Douglas MacKay and Andrea Wong. Consumer attitudes about the role of multivitamins and other dietary supplements: report of a survey. Nutrition Journal 2015, 14:66. doi:10.1186/s12937-015-0053-9. Published: 2 July 2015. http://www.nutritionj.com/content/14/1/66/abstract
Bailey RL, Gahche JJ, Miller PE, Thomas PR, Dwyer JT. Why US adults use dietary supplements. JAMA Intern Med. 2013 Mar 11;173(5):355-61. doi: 10.1001/jamainternmed.2013.2299. http://www.ncbi.nlm.nih.gov/pubmed/23381623
Dickinson A, Blatman J, El-Dash N, Franco JC. Consumer usage and reasons for using dietary supplements: report of a series of surveys. J Am Coll Nutr. 2014;33(2):176-82. doi: 10.1080/07315724.2013.875423. http://www.ncbi.nlm.nih.gov/pubmed/24724775
Gaziano JM, Sesso HD, Christen WG, Bubes V, Smith JP, MacFadyen J, Schvartz M, Manson JE, Glynn RJ, Buring JE. Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial. JAMA. 2012 Nov 14;308(18):1871-80. http://www.ncbi.nlm.nih.gov/pubmed/23162860
Guallar E, Stranges S, Mulrow C, Appel LJ, Miller ER. Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements. Ann Intern Med. 2013;159:850-851. doi:10.7326/0003-4819-159-12-201312170-00011