Not everyone can eat nutrient-dense foods for every meal. According to the Centers for Disease Control and Prevention, the average American consumes only one fruit and one or two vegetables per dayi. This may be one reason why millions of people do not meet the daily intakes, known as Recommended Dietary Allowance (RDA), for some vitamins and minerals provided by the United States Department of Agriculture (USDA)ii. If individuals fall short of RDA values, dietary supplements may help provide vital micronutrients required for optimal health that are not consumed through a daily diet.
Micronutrients, including vitamins and trace minerals, support a variety of physiological functions within humans and other living things. Vitamins are complex organic moleculesiii, and minerals are mostly inorganic chemical materials that can be found in nature in the form of deposits or salts. Both are needed for biological processes.
While there are several important vitamins and minerals to the body, 13 vitamins, are considered “essential,” for normal cell function, growth and developmentiv. These include four fat-soluble vitamins- A, D, E and K, and nine water-soluble vitamins – C, B1(thiamine), B2 (riboflavin), B3 (niacin), Pantothenic acid, Biotin, B6, B12 and Folate (folic acid). There are 15 minerals that are considered “essential” for proper bodily function, and they include calcium, phosphorous, magnesium, iron, copper, potassium, sodium, chloride, sulfur, iodine, fluoride, cobalt, selenium, manganese and zincvi.
In rare instances, states of clinical (“true”) deficiencies occur with the extended avoidance of certain vitamins or minerals; such conditions include deficiencies like Scurvy (vitamin C deficiency) or Rickets (vitamin D deficiency). Conversely, extremely high levels of vitamins and minerals that exceed recommended intakes, are not necessarily beneficial for the human body and may actually be harmful. For example, people with Wilson’s diseasevii,a rare genetic disorder that causes excess copper to accumulate in vital organs like the liver and brain, require a lower intake of copper from daily nutrientsviii. Similarly, too much vitamin A can cause birth defects, and excess amounts of vitamin E may increase the risk of hemorrhagingix.
On a more positive note, recent studies have shown how consuming dietary supplements can assist the absorption of vitamins and minerals found naturally in foods. One study, by The American Journal of Clinical Nutrition, points to the way dietary supplement use is linked to higher intakes of minerals. In the study, individuals who took mineral-containing supplements had higher mineral intakes from food sources in the diet than did non-users.x
Although supplements may provide a greater intake of valuable micronutrients, the question remains as to whether there is adequate absorption of these nutrients and exactly what benefit they may add. Recent investigation of this question includes results from a studyxi published in the Journal of Pediatrics, which assessed the effects of dietary supplements on vitamin absorption in children. In children older than 8 years, dietary supplements were shown to add micronutrients to diets inadequate for crucial vitamins and minerals like magnesium, phosphorous, and vitamins A, C, and E. Children 2-8 years old, on the other hand, had nutritionally satisfactory diets regardless of supplement use.
This new bulk of literature examining the effects of vitamins and minerals may help redirect current thinking on the use of dietary supplements for children and adults. Often, supplements are used in an attempt to increase life expectancy, however a more immediate goal may be to provide individuals with micronutrients that are often lacking on a daily basis in typical diets. To ascertain key deficiencies or overabundances of vitamins and minerals for an individual’s daily dietary needs, a blood test can be administered by a medical practitioner.
Since everyone’s nutritional requirements are unique, it may be beneficial to monitor one’s diet, observe how it affects one’s health, and identify where supplements may be of use. Using the recommended micronutrient intake ranges provided by the USDAxii will help increase mindfulness of the essential vitamins and minerals needed for an optimal diet. Deficiencies or excesses can then be targeted through diet first, and secondarily with supplements, if needed.