Often, multivitamin/mineral products (MVMs) are falsely labeled and exceed the quantity of ingredients that are actually in the products compared to the amount labeled on the bottle. A scientific study conducted by Andrews et. al., analyzes the health benefits and harm that excessive MVMs can cause in relation to the Tolerable Upper Intake Levels and the Recommended Dietary Allowances.
Multivitamin/mineral products (MVMs) are supplements that are composed of a combination of minerals and vitamins. Taking supplementary vitamins has become very popular in North America as many people are moving towards a healthier lifestyle and trying to find ways to bring their vitamin and mineral deficiencies up to an optimal level. However, scientific literature has had mixed results on the efficacy and hype over MVMs on maintaining health and disease prevention based on the quantity depicted on the label. Thus, a recent study published in the American Journal of Clinical Nutrition tested this hypothesis to further determine if the measured amount of ingredients matched the content on the label to compare adult intake of MVMs with the Recommended Dietary Allowances (RDA) and Tolerable Upper Intake Levels.
This study was conducted on adult MVMs and estimated the relation between label and analytic values for 18 vitamins and minerals in products representative of the US market. It included 3164 observations for vitamins and 2545 observations for minerals. Following this, the percentage difference in the nutrient content that was claimed on the label was compared with the ingredient amount analytically measured. A regression analysis used for each nutrient was implemented to assist in understanding the meaning of the percent differences of the actual amount versus the amount claimed on the label.
Based on this, the results revealed that 12 of 18 nutrients had labeled amounts at or above RDAs. The MVMs that were labeled above or at the maximum level of the RDA were also found to have the highest shares in the market. Furthermore, the average of the measured ingredients was higher than the labeled amounts, where the mean percentage difference between both values were between 1.5-13% for copper, manganese, magnesium, niacin, phosphorus, potassium, folic acid, riboflavin and vitamins B12, C and E. Where most of the minerals and vitamins were above the amount portrayed on the label, one ingredient, thiamin, had an amount that was slightly below the label in comparison to what the label stated for all the MVMs used in this study. On the plus side, it was found that the products with the 6 nutrients (calcium; magnesium; and vitamins A, D, C, and E,) that were labeled above their Tolerable Upper Intake Level, had low market shares. Therefore, fewer people were at risk for consuming MVMs that had excessive vitamins and nutrients.
While the models used in this study were detailed and high in accuracy in terms of quantitative data produced, it does not explain possible explanations behind why some products had a higher market sale than others. Since the results are based on a portion of MVMs on the market and is compared to quantitative values from the Tolerable Upper Intake Levels and the Recommended Dietary Allowances, it does not show an accurate representation of the effects of excessive amounts of minerals and vitamins on the human body, but rather an estimate of general precautions. Further studies related to this topic are important to determine how many consumers take MVMs or even combine them with an intake of higher dosage single vitamins, minerals, or certain foods that could possibly contain the same vitamins, which raises safety concerns if the Tolerable Upper Level Intake is exceeded. Therefore, nutrient overexposures from supplements together with foods may have unintended health consequences but cannot be said for sure without further research.
Written By: Seema N. Goolie, BSc