Most Americans Have Inadequate Intakes of Vitamins and Minerals: Can Supplements Help?
Sponsored by the Campaign for Essential Nutrients
Vitamin and Mineral Intakes Below Requirements
Many health professionals might be surprised to find that numerous studies show over 90% of Americans get less than the Estimated Average Requirement (EAR) or Adequate Intake (AI) for one or more vitamins and minerals in their diets.1-5 Specifically, the 2015-2020 Dietary Guidelines for Americans (DGAs) identified potassium, dietary fiber, choline, magnesium, calcium, and vitamins A, D, E, and C as nutrients, “consumed by many individuals in amounts below the (EAR or AI) levels,” with vitamin D, calcium, dietary fiber, potassium, and iron (for young children and women who are pregnant or capable of becoming pregnant) called out as “nutrients of public health concern.” 6 Much of the data on nutrient intake and status comes from the National Health and Nutrition Examination Survey (NHANES), a nationally projectable yearly assessment by the National Center for Health Statistics. 7
Inadequate nutrient intakes can lead to deficiencies. For example, the Centers for Disease Control and Prevention (CDC) estimates that, based on standard biomarkers of nutrient status, 30 million Americans (10.5%) have vitamin B6 deficiency, with higher rates among non-Hispanic blacks (15.7%) and those over 60 years old (16%). Additionally, 23 million Americans (8.1%) have vitamin D deficiency, with greater prevalence among non-Hispanic blacks (31.1%) and Mexican-Americans (11.3%). 8
The Role of Dietary Supplements
According to the DGAs, although nutritional needs should be met primarily from food, “In some cases, fortified foods and dietary supplements may be useful in providing one or more nutrients that otherwise may be consumed in less than recommended amounts” or “are of particular concern for specific population groups.” 6
NHANES analyses have shown improvements in nutrient adequacy among individuals using a multivitamin/multimineral supplement (MVMS) and/or a single-nutrient supplement. 1-3 However, the studies likely underestimated the impact of supplement use because they compared users with the entire NHANES sample, which included both supplement users and nonusers; and did not take into account the frequency of supplement use, lumping occasional users (e.g., only once per month) with daily users. 9
To more precisely determine the effect of dietary supplementation on nutrient adequacy, Blumberg and colleagues analyzed nutrient intakes from food and supplements, categorized by frequency of use, among 10,698 adults aged 19 years and older participating in NHANES 2009-2012. They found that more frequent use of MVMS was associated with higher rates of nutrient adequacy than low frequency of use or no use (Figure). For example, 98% of individuals who reported taking a MVMS regularly (25 or more days per month) achieved intakes of vitamin D at or above the EAR versus only 4% of those who reported not taking a supplement. Similarly, a greater proportion of individuals who reported taking a single-nutrient supplement 8.5 or more days per month versus supplement nonusers achieved intakes at or above EAR levels for calcium (81% vs 62%), magnesium (73% vs 42%), vitamin C (91% vs 50%), vitamin D (77% vs 4%), and vitamin E (79% vs 12%). 9
What to Tell Our Patients
Evidence clearly shows that many Americans obtain less than the required amounts of a number of vitamins and minerals, and that dietary supplement use increases intakes and reduces rates of nutritional inadequacies. When counseling patients, health professionals should emphasize the value of obtaining nutrients from a balanced diet. However, for patients who may be unable to obtain sufficient nutrients from diet alone, a dietary supplement can help ensure adequate intakes. And because the benefits of supplements are most pronounced in those who use them frequently (e.g., daily), the importance of taking them on a regular basis should also be communicated.
1 Wallace TC, McBurney M, Fulgoni VL 3rd. Multivitamin/mineral supplement contribution to micronutrient intakes in the United States, 2007-2010. J Am Coll Nutr. 2014;33(2):94-102.
2 Bailey RL, Fulgoni VL 3rd, Keast DR, Dwyer JT. Examination of vitamin intakes among US adults by dietary supplement use. J Acad Nutr Diet. 2012 May;112(5):657-63.
3 Fulgoni VL 3rd, Keast DR, Bailey RL, Dwyer J. Foods, fortificants, and supplements: Where do Americans get their nutrients? J Nutr. 2011 Oct;141(10):1847-54.
4 Bailey RL, Fulgoni VL 3rd, Keast DR, Dwyer JT. Dietary supplement use is associated with higher intakes of minerals from food sources. Am J Clin Nutr. 2011 Nov;94(5):1376-81.
5 Agarwal S, Reider C, Brooks JR, Fulgoni VL 3rd. Comparison of prevalence of inadequate nutrient intake based on body weight status of adults in the United States: an analysis of NHANES 2001-2008. J Am Coll Nutr. 2015;34(2):126-34.
6 U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at http://health.gov/dietaryguidelines/2015/guidelines/.
7 Centers for Disease Control and Prevention, National Center for Health Statistics. About the National Health and Nutrition Examination survey. Available at: http://www.cdc.gov/nchs/nhanes/nhanes2011-2012/overview_g.htm. Accessed March 29, 2016.
8 Centers for Disease Control. Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. population. Available at http://www.cdc.gov/nutritionreport/pdf/4Page_%202nd%20Nutrition%20Report_508_032912.pdf. Accessed November 30, 2015.
9 Blumberg JB, Frei B, Fulgoni VL 3rd, Weaver CM, Zeisel SH. Vitamin and mineral intake is inadequate for most Americans: What should we advise patients about supplements? J Fam Pract. 2016;65(9):S1-S8.