16.8 The Basics of Vitamins and Minerals

The Importance of Vitamins and Minerals

Vitamins are organic compounds that perform specific and important functions in the body. Many vitamins act as coenzymes, meaning they activate specific enzymes that affect the rates of chemical reactions in the body; for example, certain vitamins contribute to the conversion of carbohydrate, protein, and fat into energy (Bourre, 2006a). Some vitamins are antioxidants, which means they prevent or repair cell damage (Bourre, 2006a). All vitamins are essential. Additionally, some other vitamin-like micronutrients, such as choline, are also essential.

Minerals are naturally occurring inorganic solids; only some of them are essential. The essential minerals play important roles in nerve reactions and muscle contractions, and some serve as cofactors—or sparks—for important enzymatic reactions. For example, magnesium activates enzymes involved in the formation of energy and proteins. Minerals are also important structural components of bones, teeth, cartilage, and other tissues. Further, some serve as electrolytes, maintaining an adequate amount of water in the body and neutralizing body fluids if they become too basic or acidic.

If an essential vitamin or mineral isn’t consumed in adequate amounts, symptoms can occur of deficiency related to its function within the body. For example, being deficient in vitamin D can lead to softening of bones, bone pain, muscle pain and weakness, and increased risk of osteoporosis (Linus Pauling Institute Micronutrient Information Center, 2017; National Institutes of Health Office of Dietary Supplements, 2016). The fat-soluble vitamins—A, D, E, and K—can be stored in body fat, the liver, and other parts of the body, so it can take a while for deficiencies of them to develop and become evident. In contrast, symptoms of water-soluble vitamins develop quickly because only small amounts of them can be stored in the body; excess is generally just excreted via urine.

Commonly Under-consumed Vitamins and Minerals

The Linus Pauling Institute’s Micronutrient Information Center at Oregon State University provides lists of foods that are considered good sources of each of the following commonly under-consumed vitamins and minerals by Americans (U.S. Department of Agriculture, U.S. Department of Health and Human Services, 2015); consuming these foods regularly can help ensure adequacy and prevent symptoms of deficiency.

• Potassium
• Magnesium
• Calcium
• Iron
• Vitamin A
• Vitamin C
• Vitamin D
• Vitamin E
• Choline

Overconsumption of Vitamins and Minerals

Many vitamins and minerals have what’s been determined a tolerable upper intake level—UL—the maximum daily amount beyond which adverse effects are likely to occur. Regular consumption beyond this level can cause toxicity and be dangerous, sometimes even fatal. So, while it’s important to get enough of the essential vitamins and minerals, we also want to avoid getting too much of them.

Sodium is an essential mineral that’s often over-consumed in the average Western diet. Getting too much sodium in the diet is associated with high blood pressure, heart disease and stroke, kidney problems, stomach cancer, and even bone loss and osteoporosis (Harvard T. H. Chan School of Public Health, 2015a; American Heart Association, 2014). Very few foods contain much sodium naturally; whole foods like fruits and vegetables are naturally low in sodium. A recent study showed that approximately 71% of the sodium in a typical American diet comes from salt added to food in commercial processing, including foods at restaurants (Harnack, et al. 2017). Processed foods that are particularly high in sodium include frozen meals, boxed mixes, canned soups, snack foods like crackers and chips, salad dressings and other condiments, and cheese—particularly American cheese. You might be surprised by how much sodium is in some food products.

Eating a wide variety of whole foods from all of the food groups, especially plants, helps ensure adequate intake of all of the essential vitamins and minerals without getting too much of any particular one.

Benefits of Whole Foods Over Micronutrient Supplements

Surpassing the UL for any given vitamin or mineral generally isn’t likely to occur with balanced consumption of a variety of whole foods. Further, eating a whole food endows more benefits than extracting its components and consuming them separately. For example, eating an orange provides fiber, water, and other nutrients in addition to vitamin C. Phytonutrients are biologically active compounds produced by plants to protect themselves from enemies, such as viruses, bugs, and other things that want to eat them. Phytonutrients are beneficial not only to plants, but also to humans, and their consumption has been associated with beneficial effects, such as regulating blood glucose, improving lipid profiles, and reducing the risk of cardiovascular disease and certain cancers (Liu, 2003; Schlemmer, Frølich, Prieto, & Grases, 2009). Thousands of phytonutrients have been isolated from plants, and some are the basis for many commercial and herbal medications used today for the prevention and treatment of a wide range of health problems. However, what remains to be discovered is how the compounds work together as part of the plant’s protective mechanism. If one compound is isolated and removed—for a supplement, for example—the question still remains about the real benefits humans get from consuming that single compound (Lui, 2003; Lerman et al., 2014). The various components of whole foods interact in ways that can’t necessarily be replicated in supplements.

Nutritional Supplements: To Take or Not to Take?

Supplements and plant-based interventions designed to enhance wellbeing or treat disease are used world-wide and have been throughout human history. Regardless of the reasons behind their use, individuals deserve to know that the supplements they are using contain what they are supposed to and are safe. Micronutrient supplements and plant-based remedies are not reviewed and approved for safety and effectiveness by the FDA before they are marketed to consumers because they are not drugs. Supplement manufacturers are required to have evidence that their product is safe, and they are supposed to follow labeling guidelines to avoid misleading consumers with claims on their labels, but unfortunately, unbiased scientific evidence for many dietary supplements and herbal remedies is severely lacking, as is their regulation.

Some supplements and herbal products have been found to contain things that aren’t on the ingredients list—contaminants and fillers—some of which may pose health risks to consumers, and some don’t actually include what they claim to offer, meaning that they’re impure and their labels inaccurate (Newmaster, Grguric, Shanmughanandhan, Ramalingam, & Ragupathy, 2013; O’Connor, 2015). Several organizations—U.S. Pharmacopeia, ConsumerLab.com, and NSF International—offer quality testing to help assure consumers that the product was manufactured properly, contains the ingredients the label says it does, and does not contain harmful levels of contaminants. If you decide to take a supplement, we recommend that you choose a brand that has a seal of approval from one of these organizations or that you receive from a trusted health professional.

It’s probably safe and may be appropriate for most people to take a single daily dose of a basic multivitamin and mineral supplement. Some health professionals recommend that everyone do this because many Americans are not consuming adequate amounts of a number of micronutrients. Some reasons for inadequate consumption of micronutrients include soil mineral depletion and the fact that many fruits and vegetables are picked before peak ripeness so they can be shipped long distances and have a longer shelf life. But, it’s not an official recommendation and continues to be debated, and it is possible to achieve adequate intake of all the nutrients the body needs without taking a supplement when a variety of whole foods are consumed.

Taking high doses of supplements increases the risk of getting too much of whatever is taken, so we should avoid taking doses that are more than the UL for any specific vitamin or mineral—particularly the fat-soluble vitamins. Considering we also get nutrients from the foods and beverages we consume, it’s probably safer to take a dose that’s below the UL or just the RDA or AI, unless directed otherwise by a trusted health professional.

Supplementation of specific vitamins or minerals, or other products, may be appropriate for some individuals in certain circumstances, such as those who:

• have an existing deficiency of a specific micronutrient.
• have certain illnesses or diseases that may require higher amounts of specific micronutrients.
• are pregnant or lactating.
• are taking a medication that affects absorption of certain micronutrients.
• aren’t getting what they need from their diets and can’t or aren’t likely to—for example, because they’re following a vegan diet.

If you think you may benefit from a micronutrient supplement, we suggest that you talk with a trusted health professional who can help you determine whether it’s necessary and, if so, identify an appropriate dose for you to take. After all, why spend money on something that you don’t need and that could pose risk?

Finally, note that micronutrient supplements may interact with certain medications, so, if you take any medication, it’s particularly important that you discuss your use of supplements with a trusted health professional. Some vitamins and minerals can also interact with each other or cause stomach upset if taking more than one supplement, it may be ideal to take them at different times throughout the day and take them with a meal or snack.