With so many Americans routinely takingdietary supplements, it's important to have the best science backed information on what you should be putting into your body. In general, studies of people who eat diets rich in fruits, vegetables, nuts, whole grains, and fish show that they consume higher levels of vitamins and minerals from these foods and also have a lower risk of many diseases, including heart disease, stroke, diabetes, and cancers. On the other hand, trials testing the effect of selected vitamins or minerals as pill supplements have mostly shown very little influence on health. The main exception may be fish oil supplements, for which some trials show a lower risk of heart disease and possibly vitamin D.
This report explains the different types of studies used to assess the benefits and safety profiles of various nutrients. It also includes the recommended minimum and maximum amounts of the vitamins and minerals you should consume, as well as good food sources of each. The special section—“Does your diet deliver the daily recommended dose?”—will help you determine whether you’re getting sufficient amounts of vitamins and minerals from your diet, and what to do if you’re not.
Prepared by the editors at Harvard Health Publishing in consultation with Howard D. Sesso, ScD, MPH, Associate Epidemiologist, Brigham and Women’s Hospital, Associate Professor of Medicine, Division of Preventive Medicine, Harvard Medical School. 53 pages. (2022)
Vitamins vs. minerals
What distinguishes a vitamin from a mineral? A vitamin, simply put, is an organic substance—one produced by a plant or an animal—that is required in small amounts for human life. (The first syllable, vit-, comes from the Latin word for “life.”) With the exception of vitamin D, vitamins cannot be synthesized in the body and must come from food. They are therefore considered essential micronutrients.
A mineral is an inorganic element—one that comes originally from rocks, soil, or water (though it may enter your diet through a plant that has absorbed it from the environment, or an animal that has eaten such a plant). There are many minerals, but only certain ones are necessary for human health.
Another difference is that vitamins have complex structures that can be broken down by heat, air, or acid. Minerals are simpler elements that hold on to their chemical structures. That means minerals can easily find their way into your body through the plants, fish, animals, and fluids you consume. It’s more difficult to shuttle vitamins from food into your body, because cooking, storage, and simple exposure to air can inactivate these more fragile compounds.
Despite their differences, vitamins and minerals often work together. For example, vitamin D enables your body to pluck calcium from food that is passing through your digestive tract, rather than harvesting it from your own bones. Vitamin C helps you absorb iron. However, the interplay of micronutrients isn’t always cooperative. For example, too much vitamin C can block your body’s ability to assimilate the essential mineral copper.
There are a couple other distinctions to be aware of. Vitamins are subdivided into two categories— water-soluble and fat-soluble—with implications for your diet. Minerals, too, are subdivided into major minerals and trace minerals, depending on how much you need of each. Many vitamins and some minerals are also classified as antioxidants.
