Updated 25 October 2021 Jae Haroldsen

Dietary supplements are anything (pill, capsule, tablet, drink, bar, chewable, or gummy) taken by mouth to supplement the normal diet. Supplements can contain vitamins, minerals, enzymes, protein, amino acids, herbs, botanicals, extracts, or other certain substances.  

Dietary Supplement Categories 

Dietary supplements are broken down into four basic categories.  

  • Vitamin and Minerals 
  • Specialty Supplements designed to support a specific function or structure in the body. (i.e. fiber, melatonin, probiotics, etc) 
  • Herbal and Botanical Supplements from plants (vegetables, fruits, roots, stems, flowers, and roots) 
  • Sports Nutrition and Weight Management 

Federal Regulation of Dietary Supplements 

In 2020, the global dietary supplement market was valued at $140 Billion. According to Grand View Research, increasing consumer awareness and education concerning nutrition and personal health is driving the market along with escalating hectic lifestyles. 

However, supplements are not intended to replace the nutrition obtained from consuming healthy food. Before jumping on the band wagon and loading up on supplements there are few things worth considering. 


  1. The Food and Drug Administration (FDA) does not review dietary supplements for effectiveness or safety before they are marketed. 

Though dietary supplements can be potent, the FDA puts regulation compliance in the hands of manufacturers, distributors, and brand owners. Once a dietary supplement is on the market, the FDA can take action against misbranded or adulterated supplement products. They also track consumer reported side-effects through the US Health and Human Services Safety Reporting Portal. 

To ensure FDA regulations are met, Amazon.com (a supplement distributor accounting for as much as 77% of online supplement sales) now requires stringent documentation to sale dietary supplements on their site. They require: 

  • A certificate of analysis (CoA) from a certified testing laboratory or an in-house laboratory with GMP certification from an Amazon approved third-party program. 
  • Images of all sides of the supplements label, including the nutrition facts label, ingredients list, warnings, and certification logos. 

   2. Scientific research varies widely.  

Some types of supplements are well studied while others are not. To determine if a supplement is well studied, log onto the National Institute of Health (NIH): Office of Dietary Supplement’s consumer fact sheets. NIH helps consumers make informed decisions regarding supplement use by giving the daily recommended daily amounts (RDA), benefits, and warnings. 

For example, the calcium consumer fact sheet lets us know calcium is vital for strong bones, muscle movement, and the nervous system. Getting too much calcium can cause constipation and increase the risk of kidney stones and prostate cancer. NIH also sets an upper limit for daily calcium intake and relays the types of medications calcium supplements may interact with. 

  3. Supplements available for consumer purchase may differ from products used in research studies. 

You discover whey protein supplements may help build muscle and shed fat. You might be tempted to purchase the first whey protein supplement you see. But do you know how much protein you should be consuming? Do you know if you take more then 20 g of readily digestible protein (whey protein) in one sitting, the body either oxidizes or passes it though the kidneys? 

For chronic joint pain, I’ve taken turmeric supplements for years. But it wasn’t until I did my research, I discovered I need a turmeric supplement with piperine in it. The piperine increases turmeric bioavailability by 2,000 percent. 

Before using dietary supplements, seek appropriate medical advice. For dosage amounts and warnings, check the NIH consumer fact sheets or do some research on Examine.com. 

  4. Health/Structure/Function Claims 

By law, dietary supplement label claims and advertising cannot claim to diagnose, treat, cure, mitigate, or prevent any disease. However, they may make claims to how the supplement relates to health or how it affects the structure/function of the body.  

Health Claims: The proper wording for dietary supplements to make a health claim includes words like promotes, supports, helps, and aids. For example, vitamin C supports immune health. 

Structure or Function Claims: These claims relate the facts of the substance to maintaining the health of a specific body structure or function. For example, fiber maintains bowel regularity. 


What are the risks of dietary supplements? 

The body is a complex chemical laboratory. Supplements contain active chemical ingredients. Side-effects are most likely to happen when taking large doses of supplements, taking many different kinds of supplements, or taking supplements that interact with prescribed medications. 

  • NIH warns fortified foods and beverages contain supplements, too. The recommended RDA includes all consumed sources of a given substance.  

For example, if you take a multi-vitamin with 100% daily value (DV) of Vitamin A and then drink an immune boosting beverage with 100% DV of Vitamin A, you have consumed twice the recommended amount without even adding in the vitamin A naturally found in the food you consumed.  

The upper limit for Vitamin A is roughly three times its RDA. Too much Vitamin A can cause nausea, headaches, dizziness, coma, death, and birth defects. 


  • NIH recommends using caution when pregnant, breastfeeding, or giving supplements to children unless prescribed by a medical professional. Supplement use for these demographic groups is not well researched. 
  • Some supplements negatively interact with some prescribed medications. High doses of supplements are not a substitute for prescribed medication. 
  • Across the US, an estimated 23,000 emergency room visits are attributed to supplements every year. Commonly these are attributed to weight loss or energy drink supplement use in young adults, micronutrient overdoes in unsupervised children, and older adults having swallowing issues. 
  • Some supplements may interfere with anesthesia or increase the risk of bleeding and should not be taken for up to two weeks before surgery. Well before any scheduled surgery, consult your surgeon about what supplements you are taking. 


What are the benefits of dietary supplements? 

Micronutrients, macronutrients, herbs, and botanicals all have a place in the body’s complex chemical dance. If you don’t eat a variety of healthy food, supplements can fill nutrition gaps. Some supplements have been proven to improve overall health and well-being and help manage some conditions. 

Supplements can support, aid, and help conditions like chronic pain, stress and anxiety, insomnia, strong bones, heart disease, the immune system, and more. Talk to your medical professional about supplements and dosages that may be right for you. Be an informed consumer by consulting the NIH consumer fact sheet for individual supplement information. 

If you follow a restricted diet, including a keto, Atkins, vegan, or vegetarian, you may benefit from taking a dietary supplement geared to the missed nutrients in your diet. 


What vitamins are worth taking? 

Besides taking a multivitamin to fill nutrition gaps, Nutritionist Dawn Lerman, MA, CHHC, LCAT recommends the best supplements worth taking are Vitamin D, Calcium, B Vitamins, Magnesium, and Zinc. 

Our skin manufactures Vitamin D from exposure to sunlight, but this only works well if you live south of the 34-degree latitude line. Vitamin D is essential for calcium absorption and hence strong bones. Vitamin D also plays a role in the immune system and energy levels. 

Food sources high in Vitamin D include fortified foods and fatty fish. Small doses of Vitamin D are found in egg yolk, mushrooms, beef liver, and cheese. 

  • Calcium 

Bones and teeth are made from calcium. Lack of sufficient calcium puts individuals at risk for weak bones or osteoporosis especially in the elderly. Calcium is also an important part of body’s hydration/electrolyte balance. 

Food sources high in Calcium include dairy, kale, broccoli, and fortified foods. 

  • B Vitamins (Folic Acid & B12) 

To prevent neural tube birth defects, the Center for Disease Control and Prevention (CDC) urges all women of reproductive age to supplement their diet with 400 mcg of folate acid (Vitamin B9) in addition to eating a healthy diet. 

Most food sources of Vitamin B12 are animal-based. Since B12 keeps blood and nerve cells healthy and manufactures DNA (genetic cell coding), vegans and vegetarians should take a supplement with 1-2 mcg daily. Besides other things, a Vitamin B12 deficiency may lead to megaloblastic anemia, causing a person to feel tired or weak.  

  • Magnesium 

Magnesium is involved in several systems in the body. It helps make bone, protein, and DNA. It regulates muscle and nerve functioning, blood pressure, and blood sugar levels. Magnesium may also help reduce stress and promote better sleep. 

Food sources high in magnesium include food often left out of the American diet, including green leafy vegetables, soy beans, artichoke, winter squash, nuts, and seeds. 

  • Zinc 

Zinc supports the immune system to fight off viral and bacterial infections. It is also required for the body to form proteins and DNA, making it essential for wound healing.  

People dealing with stress and the elderly may be zinc deficient especially in the US since our diet typically doesn’t include foods high in zinc. Shelled seafood (oysters, crabs, lobster) contains high levels of zinc. NIH recommends consuming 8-12 mg of zinc daily. 


How to know if a dietary supplement is of good quality? 





“Dietary Supplements Market Size, Share & Trends Analysis Report By Ingredient (Vitamins, Proteins & Amino Acids), By Form, By Application, By End User, By Distribution Channel, And Segment Forecasts, 2021 – 2028.” Grand View Research. 2021. https://www.grandviewresearch.com/industry-analysis/dietary-supplements-market 


“Using Dietary Supplements Wisely.” National Center for Complementary and Integrative Healthhttps://www.nccih.nih.gov/health/using-dietary-supplements-wisely 


“Calcium Consumer Fact Sheet.” NIH. 2021. https://ods.od.nih.gov/factsheets/Calcium-Consumer/ 

Schoenfeld, Brad Jon, and Alan Albert Aragon. “How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution.” Journal of the International Society of Sports Nutrition vol. 15 10. 27 Feb. 2018, doi:10.1186/s12970-018-0215-1 

Hewlings, Susan J, and Douglas S Kalman. “Curcumin: A Review of Its Effects on Human Health.” Foods (Basel, Switzerland) vol. 6,10 92. 22 Oct. 2017, doi:10.3390/foods6100092 

“What You Need to Know.” NIH. https://ods.od.nih.gov/factsheets/WYNTK-Consumer/ 

“Vitamin A Consumer Fact Sheet.” NIH. 2021. https://ods.od.nih.gov/factsheets/VitaminA-Consumer/ 

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Kassel, Gabrielle. “According to Nutritionist, These are the 7 Ingredients Your Multivitamin Should Have.” Healthline. 2020. https://www.healthline.com/health/food-nutrition/best-vitamins-to-take-daily 

“Folic Acid Helps Prevent Serious Birth Defects of the Brain and Spine.” CDC. 2021. https://www.cdc.gov/ncbddd/folicacid/features/folic-acid-helps-prevent-some-birth-defects.html 

“Vitamin B12 Fact Sheet for Consumers. NIH. 2021. https://ods.od.nih.gov/pdf/factsheets/VitaminB12-Consumer.pdf 

Stanton, Taylor. “Online Vitamin Sales are Growing Faster than the Rest of e-commerce.” Rakuten Intelligence. 2019. https://www.rakutenintelligence.com/blog/2016/online-vitamin-sales-growing-faster-rest-e-commerce 

Long, Josh. “Amazon’s GMP policies not perfect, but praised by supplement stakeholders.” Natural Products Insider. 2021. https://www.naturalproductsinsider.com/regulatory/amazons-gmp-policies-not-perfect-praised-supplement-stakeholders