- Nutrition
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Melissa Rifkin, MS, RD, CDN
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Medically reviewed byMelissa Rifkin, MS, RD, CDN
Melissa Rifkin is a Connecticut-based registered dietitian with over 15 years of experience working in the clinical setting.
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Updated on May 03, 2022
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Marley Hall
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Fact checked byMarley Hall
Marley Hall is a writer and fact checker who is certified in clinical and translational research. Her work has been published in medical journals in the field of surgery, and she has received numerous awards for publication in education.
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Dietary supplements contain ingredients that can help supplement one’s diet. They include vitamins, minerals, fats, proteins, carbohydrates, enzymes, and probiotics and can provide key nutrients that may help fill nutritional gaps. They can also aid in managing certain health conditions or condition-related symptoms.
Supplements often come in the form of pills, tablets, capsules, powders, extracts, or liquids. Examples include your daily multivitamin, protein powder, fish oil capsules, and more. Learn about popular supplements and what you may want to consider if you choose to add them to your routine.
Frequently Asked Questions
Do supplements work?
There’s a lot of confusion surrounding supplements and whether or not they work. Some supplements can enhance your health (especially if you have a diagnosed deficiency, eat a diet that restricts certain foods, or are going through a life stage like pregnancy), while others may not make a noticeable difference. Still, others might cause negative effects if you consume too much or if medications you are taking interact with the supplement. If you eat a balanced, nutrient-rich diet and don't have any health issues, there’s usually little need for nutritional supplements.
Learn More:The 9 Best Supplements, According to a Dietitian
Are supplements safe?
Supplements aren’t authorized for safety by the FDA before they come to market, so many wonder whether supplements are safe. There are side effects of taking supplements. Some products may interfere with medications or increase the risk of health complications. Always speak with a health care provider to explore whether supplements are right for you.
Learn More:Benefits and Risks of Dietary Supplements
Do collagen supplements work?
Collagen supplements are popular among those who want to reap the beauty benefits, such as firmer skin and stronger nails; however, there is little concrete evidence that they actually work. Some evidence suggests collagen may alleviate joint pain. Other research supports collagen's ability to increase skin elasticity and hair strength and growth.
There is less evidence supporting the use of collagen for nail strength, but it is possible that collagen supplements might be beneficial. Regardless of these benefits, some collagen powders are significant sources of protein and can be used as protein powders.
Learn More:Foods That Are Good for Your Skin
What is NAC supplement?
NAC stands for n-acetyl cysteine, which is an antioxidant. NAC supplements are associated with several benefits like reduced inflammation, cancer prevention, and brain health.
Learn More:The Health Benefits of Antioxidants
How should you take calcium supplements for best absorption?
Always speak with a health care provider to discuss whether supplementation is appropriate for your individual health concerns. If recommended, consult the provider about dosage and instructions. To increase the absorption of calcium, you may want to take it in small doses. Split your dose into two doses taken at different times of the day. You can also take calcium with vitamin D to increase its absorption.
Learn More:Calcium Requirements and Dietary Sources
Is an iron supplement necessary?
If you eat an iron-rich diet and have no issues with absorption, an iron supplement isn’t usually necessary. The most easily absorbed form of iron, called heme iron, is found in animal foods, such as beef, oysters, chicken, and turkey. Though iron from plant foods is less readily absorbed, pairing iron-rich plant foods with vitamin C-rich foods may increase iron absorption. Plant sources of iron include fortified cereals, dark leafy greens, beans, and quinoa.
People with low levels of iron or other health conditions may need to take an iron supplement as directed by a health care provider. Those at the highest risk of deficiency are those who follow vegetarian or vegan diets, those with absorption issues, pregnant people, young children, adolescent girls, and people with heavy menstrual periods.
Learn More:Symptoms of Iron Deficiency
Key Terms
Minerals
Minerals are micronutrients, meaning they are nutrients we need to consume regularly in small quantities in order to survive. They are naturally found in many foods, and they’re also available in supplements. Examples of minerals include calcium, iron, magnesium, and potassium.
Where to Find the 6 Major Minerals in Food
Herbs
Herbs are parts of plants (leaves, seeds, or flowers). They’re often used to flavor food, but they’re also found in herbal supplements due to their potential medicinal properties. Examples of herbs found in supplements include echinacea, garlic, and ginkgo.
The Health Benefits of Echinacea
Vitamins
Vitamins are among the most common types of supplements. Vitamins are essential nutrients naturally found in food, but those trying to fill nutritional gaps may turn to vitamin supplements. Vitamins are generally classified as fat-soluble (vitamins A, D, E, K) or water-soluble (vitamin C and B-complex vitamins). Fat-soluble vitamins dissolve in fat and can be stored in the body, whereas water-soluble vitamins dissolve in water and are generally excreted in urine if they cannot be used in the body.
Fat-Soluble Vitamins: Overview and Recommendations
Sports supplements
Some sports supplements, such as protein powders, creatine, electrolytes, and BCAAs may be used to support athletic training and recovery.(add existing citation here, at the end of the sentence) Ergogenic aids, or performance-enhancing substances, can be tricky, as some, such as caffeine, are legal and usually safe, whereas others, such as anabolic steroids, are potentially harmful and banned by a variety of athletic organizations.
The 6 Best Protein Powders, According to a Dietitian
Fiber supplements
While fiber is naturally found in plant foods such as fruit, vegetables, and whole grains, it’s also found in supplements made from psyllium, seeds, pectin, cellulose, and lignin. While there are many health benefits of eating a diet high in fiber-containing foods, most fibers in supplements do not support the same health benefits. However, specific fiber supplements may help improve digestion, alleviate constipation, lower cholesterol, and improve glycemic control.
The 6 Best Fiber Supplements, According to a Dietitian
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Page Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institutes of Health Office of Dietary Supplements. Background information: Dietary supplements.
National Institutes of Health Office of Dietary Supplements. Dietary supplements: What you need to know.
National Institutes of Health Office of Dietary Supplements. Background information: Dietary supplements.
Khatri M, Naughton RJ, Clifford T, et al.The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review.Amino Acids. 2021;53:1493–1506. doi:10.1007/s00726-021-03072-x
Bolke L, Schlippe G, Gerb J, Voss W. A collagen supplement improves skin hydration, elasticity, roughness, and density: Results of a randomized, placebo-controlled, blind study. Nutrients. 2019;11(10):2494. doi:10.3390/nu11102494
Kalman DS, Hewlings S. The effect of oral hydrolyzed eggshell membrane on the appearance of hair, skin and nails in healthy middle-aged adults: A randomized double-blind placebo-controlled clinical trial. J Cosmet Dermatol. 2020; 19(6); 1463-1472.doi:10.1111/jocd.13275
Mokhtari V, Afsharian P, Shahhoseini M, Kalantar SM, Moini A. A review on various uses of n-acetyl cysteine.Cell J. 2017;19(1):11-17. doi:10.22074/cellj.2016.4872
National Institutes of Health Office of Dietary Supplements. Calcium fact sheet for health professionals.
Aloia JF, Dhaliwal R, Shieh A, et al. Vitamin D supplementation increases calcium absorption without a threshold effect.Am J Clin Nutr. 2014;99(3):624-631. doi:10.3945/ajcn.113.067199
Michigan State University. Iron and vitamin C: The perfect pair?.
National Institutes of Health Office of Dietary Supplements. Iron fact sheet for health professionals.
Merriam-Webster. Micronutrient.
Academy of Nutrition and Dietetics. Supplements and ergogenic aids.
Lambeau KV, McRorie JW Jr. Fiber supplements and clinically proven health benefits: How to recognize and recommend an effective fiber therapy.J Am Assoc Nurse Pract. 2017;29(4):216-223. doi:10.1002/2327-6924.12447
