Dietary supplements constitute a multi-billion dollar industry in the United States. With revenue like this, it’s no surprise that the variety of vitamins and minerals available is soaring, as are the claims for better health. Despite the fact that over half of U.S. adults take some form of dietary supplement, few are certain about what they actually need. What’s more, many people don’t realize that vitamins and minerals are not always benign. There are risks to taking excessive doses, and, for most people, the benefits of taking a multivitamin at all are lacking.
Another important fact to remember that I cannot emphasize enough is the poor regulation of dietary supplements. By law, dietary supplements do not need to be tested for safety or effectiveness prior to marketing. Standardization is also not required of dietary supplements, which would help ensure consistent content of various ingredients between batches. Some dietary supplement manufacturers opt to be regulated by the U.S. Pharmacopeia (USP). Supplements that have a “USP” seal on their label have passed tests for purity and potency of ingredients.
So, do you need to take a vitamin/mineral supplement? While I’d like to say no, the correct answer is that it depends. A balanced diet that is rich in fruits and vegetables – especially leafy greens – should provide sufficient amounts of all the necessary vitamins and minerals. Unfortunately, the average American’s diet is far from perfect (the acronym for it is actually SAD - Standard American Diet). Furthermore, in some areas where the only produce available comes from large factory farms, the soil is often depleted in nutrients, which alters the nutrient content of the food grown in it.
Keep the key points listed below in mind when deciding whether or not to take a dietary supplement.
- Dietary supplements cannot replace food and will not make up for a poor diet. Not only are nutrients better absorbed from food, but food also contains various phytochemicals (some named, and undoubtedly some yet to be discovered) that have important roles in maintaining good health and preventing disease.
- Vitamin D is the only vitamin supplement that I fully support, especially for people who do not spend much time outside in the sun (without sunscreen) or people who live in northern areas – especially during winter. Vitamin D has been a hot topic in nutrition research for the past few years. Deficiency of vitamin D may contribute to osteoporosis and has been associated with increased rates of some cancers and autoimmune diseases.
- A vitamin B12 supplement may be necessary if you are a vegan or eat very little animal products. Vitamin B12 is only found in animal products.
- More is not necessarily better. Do not take more than 100% of the recommended daily intake of any one vitamin or mineral on a regular basis. Doing so may impair absorption (and possibly induce deficiency) of other vitamins or minerals.
- Take caution when taking supplements that contain high doses of vitamin A, beta-carotene and folic acid. Too much of these nutrients from supplements (not from food) may significantly increase cancer risk.
- Iron supplements should only be taken when there is a definite iron deficiency because of concern about relationships between iron and heart disease & cancer. Men and post-menopausal women should avoid multivitamin/mineral supplements containing iron as well as highly fortified foods.
NOTE: The above comments only apply to healthy adults. Various health conditions and diseases may alter an individual’s micronutrient needs, which may necessitate vitamin / mineral supplementation. Please speak with your RD about any vitamin questions you have and always disclose what vitamin/mineral supplements you take to your doctor & pharmacist.