As it turns out, the majority of individuals can and usually do meet their dietary recommendations for each vitamin and mineral without supplementation through their daily diet. There are only some groups of the population who benefit from taking multivitamins, and some nutrients that are beneficial when supplemented. Also, the nature of most vitamins and minerals renders supplementation, especially in multivitamin form, somewhat inefficient. Consumers may want to consider these facts when choosing supplements.

Generally, the discovery of most vitamins and essential minerals involved a large population presenting the same sickness, and an investigation into what these people had in common. What would be found in common is that their diets universally lack a certain group of food, and these foods contained one substance. When introduced to foods with this substance, the people would no longer be sick. These substances were then called vitamins, and without them, people develop problems due to deficiency.

Vitamin and mineral deficiencies are rare in today’s society, with the exception of iron deficiency anemia in women. Most deficiencies have been addressed over the years through fortification of foods and increased diet variety (Smolin, 2013.) Most grains, for instance, breakfast cereals in particular, are now are fortified (if whole grains) or enriched (if processed) to contain substantial levels of B vitamins like folate, thiamin, riboflavin, niacin and iron. A healthy adult or child of the general population can get all of his or her dietary recommendations for each nutrient through the diet without supplementation and without too much effort. The essential nutrients are consumed in adequate amounts in a normal diet.

A supplement like a multivitamin provides all or most of the discreet compounds that prevent deficiencies. However, it is important to recognize that just because vitamin A prevents a certain type of night blindness; taking vitamin A in excess does not boost or improve eye function. In fact, there is still much to be known about the short and long term effects of taking vitamins and minerals in excess.

Additionally, dietary supplements are not regulated or tested by the FDA. The FDA generally does not verify the heath claims put of dietary supplement labels, nor does it test the amount of each nutrient and its effect (Smolin, 2013). Therefore, customers should be wary of health claims as well as labeled amounts of supplements given.  

So can anyone benefit from multivitamins?

There are groups of people that can benefit greatly from a multivitamin. These groups are either nutrient deficient or at risk of nutrient deficiency. For example, pregnant women are advised to take multivitamins and supplements because they are especially prone to certain deficiencies and need special amounts of certain nutrients like folic acid to prevent fetal abnormalities (Judith, 2012). The elderly can also benefit from taking certain multivitamins because their digestive tracts may not be able to absorb certain nutrients efficiently (Judith, 2012). Those following the vegan diet or other restrictive diets may benefit from a multivitamin as well. Vegetarians, however, are not included in this group, as their diets can meet all of an individual’s nutrient needs if followed correctly (Judith, 2012). There are also a variety of medical conditions that may prevent a person from being able to consume all the nutrients they need for a variety of reasons. Healthy children and adults however, generally do not need to supplement their diet with multivitamins.

Is there any nutrient generally appropriate to supplement?

There are nutrients that the general population is lacking and are recommended in the form of a supplement. Vitamin D supplements are the only recommended supplement to all age groups, 600 IUS per day, because Americans, on average, spend a lot of time indoors or live in latitudinal areas where they cannot receive substantial sunlight to manufacture enough vitamin D precursors (Judith, 2013). This is the only nutrient many Americans physically cannot receive in adequate amounts in their diet. Nutrients that are also acceptable to supplement are Omega-3 fatty acid, folic acid, EPA and DHA (commonly found in fish oil), vitamin D, and iron if discussed with a doctor (Judith, 2013). These however, are best supplemented individually, not in a multivitamin.

Multivitamins, though packed with vitamin and minerals, are often ineffectively absorbed into the body as well as inefficiently stored. Often, supplements taken by mouth are not readily absorbed and taken into the body, and can even hinder the absorption of other essential nutrients. Iron, for instance, is a compound that not only is poorly absorbed and known to cause stomach upset, but it also binds to other nutrients like Calcium, Vitamin D and Zinc and prevents their absorption as well (Dietary Supplement Fact Sheet, 2007). For this reason iron is not recommended to be taken with meals, or in multivitamins with other nutrients (Dietary Supplement Fact Sheet, 2007). Also, much of what is packaged and labeled is readily excreted in the urine. B vitamins and vitamin C, are all water soluble in nature. This means that excess levels are not stored in the body, rather, they are excreted in the urine without use (Smolin, 2013). Many vitamins are fat soluble, meaning they are stored in the body, and not excreted over time. Because they are stored, these vitamins’ requirements do not need to be filled daily and deficiencies are rare (Smolin, 2012).

THE BOTTOM LINE:

Though there are some exceptions, for most of the general population, the cheapest, safest way to receive all the essential nutrients is through the diet.

References

Dietary Supplement Fact Sheet: Iron [Fact sheet]. (2007, August 24). Retrieved April 17, 2013,

from National Institue of Health Office of Dietary Supplements website: http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/

Judith, B. E. (2011). Nutrition Through the Life Cycle (4th ed.). Belmont, CA: Wadsworth

CENGAGE Learning.

National Institute of Medicine, F. A. N. B. (2010). Dietary Reference Intakes (DRIs): Estimated

Average Requirements. In National Academy of Sciences. Retrieved April 15, 2013, from  USDA Website: http://www.iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/5_Summary%20Table%20Tables%201-4.pdf

Smolin, L. A., & Grosvenor, M. B. (2012). iProfile (3rd ed.). Retrieved from

    http://iprofile.wiley.com/iprofile/app/

Smolin, L. A., & Grosvenor, M. B. (2013). Nutrition: Science and Applications (3rd ed.).

Somerset, NJ: Wiley and Sons.

Cara Dooley

UConn Extension Nutrition Intern

Summer 2014