The supplement business is booming! Over half of the U.S population takes vitamin or mineral supplements regularly and it is estimated that 40% of all dietary supplement sales are for vitamins and/or minerals. But since the supplement industry is not regulated by the FDA, quality and efficacy of these kinds of supplements falls into question begging the question from many savvy consumers, “Do I need to be taking a multivitamin?”
Do you need a multivitamin?
One of the most common arguments against taking a multivitamin supplement is that we can get all the vitamins and minerals we need from a well-balanced diet. However, the NHANES (National Health and Nutrition Estimation Survey) data indicates that nearly 40% of Americans do not meet the RDA or recommended daily allowance for Vitamins D, A, C, E, thiamin, folate, magnesium and calcium. Additionally, food preparation/processing often depletes the nutritional value of foods lowering the amount available to the consumer. Our soil is also depleted of many vitamins and minerals due to modern farming practices, further reducing the vitamins and minerals normally found in crops and animal meats. Additionally, insufficient digestion or inflammation along the GI tract may hinder how much of a vitamin or mineral is absorbed and utilized.
It is important to note that there is currently insufficient evidence to support the use of multivitamins to prevent specific disease outcomes, since rigorous studies are limited. However, their role is still important in that they help support metabolism, cellular health and help to avoid vitamin and/or mineral deficiencies.
While the above leads us to recommend that most people take a quality multivitamin, there are also specific conditions or disease states that might warrant supplementation as well. These include:
- Alcohol dependency
- Gastric bypass surgery
- Liver or Renal disease
- Malabsorptive disease (Inflammatory Bowel Disease or Celiac Disease)
- Cachexia or wasting diseases
- Specific genetic disorders
- Pregnancy or those trying to conceive
- Older adults
What do multivitamins usually contain?
Most multivitamins include at least 100% or more of the daily value (DV) for vitamins and minerals. Sometimes the % may be substantially higher since we do not absorb and use everything that is in a supplement. Increasing the percentage helps increase the chances of being able to use more of what is included. For fat soluble vitamins and minerals, be aware of the % DV in your supplement. Since fat soluble vitamins (A, E, D and K) and minerals (iron, zinc, calcium, magnesium, copper and manganese) can be stored in the tissues, toxicity is possible. However, because many minerals impede absorption of one another, it is unlikely that the body will use and absorb 100% of what is listed on a MVM label. Examples of these interactions include iron and calcium, iron and zinc, calcium and magnesium, and zinc and copper.
What about the forms of the vitamins and minerals?
There is a lot of debate surrounding “natural” vs. “synthetic” forms as well as whether choosing “active” forms of vitamins and minerals is best.
Some multivitamins include already activated forms of vitamins such as methylated folate (5-MTHF) and B12 (Methylcobalamin), which may provide a benefit for those who have trouble converting vitamins to their active forms (often referred to as methylation). Some studies suggest a benefit of 5-MTHF over folic acid in reducing homocysteine in the body (elevated levels are linked to cardiovascular disease), but there aren’t enough rigorous studies to make a blanket recommendation that 5-MTHF is superior to folic acid in all cases. 5-MTHF alone or blended with folic acid should be recommended when someone has the genetic variant MTHFR (which means they have trouble activating folate from food and folic acid from supplements) or when it is suspected, in those who are pregnant or trying to conceive, and when taking high dose folate supplements. We always recommend taking supplemental 5-MTHF/folic acid with Vitamin B12 since B12 is needed to utilize folate in the body.
Minerals are bound to a carrier in supplements that helps with absorption and stabilization. Oxide and carbonate molecules are frequently used with calcium, magnesium, copper and zinc. Although minerals bound to oxide actually contain more of the mineral by volume than other forms, the actual absorption and bioavailability is very low. We recommend chelated forms; those bound to amino acids or organic acids like citrate, glycinate, or malate. Additionally, calcium and magnesium are bulky minerals and the % in a multivitamin is generally low due to volume constraints. It’s usually best to supplement these minerals outside of a multivitamin format.
Vitamin E is another good example of something to watch out for in a multivitamin. Many products contain Vitamin E in synthetic form, called d,l alpha-tocopherol. This synthetic form has little to no actual Vitamin E activity in the body and should be avoided. Instead, look for mixed tocopherols on the label, or d alpha-tocopherol.
What should you look out for?
We generally recommend avoiding products that contain a lot of fillers, additives, preservatives, dyes, sugars or other sweeteners. Many one -a-day multivitamins available in drugstores contain red and yellow dyes, dextrose or maltodextrin (a starch derived from corn), polyethylene glycol, polysorbate 80 and titanium dioxide. While these ingredients have been declared safe to consume by the FDA, our recommendation is to avoid consuming these daily as they contribute to the total burden on the body and some studies show they may be carcinogenic.
An added layer of complication exists with the labeling and regulation of multivitamin supplements. The claims that companies make about vitamins and minerals are regulated, but what goes into the actual product is not. It is up to the consumer to choose brands that have integrity and good quality control standards in place. Some companies even submit to third party testing to verify that their products meet a specific standard of quality.
The bottom line here: we cannot make a blanket statement that all synthetic forms of vitamins/minerals should be avoided, but if you choose a high-quality supplement chances are the forms will be in highly bioavailable and active forms. One important note is that these will be more expensive than their synthetic counterparts so weigh the cost versus the benefit with a trusted professional who can guide you.
Guilliams, T. G. (2014). Supplementing dietary nutrients: A guide for healthcare professionals. Stevens Point, WI: Point Institute.