Medically Reviewed by Dany Paul Baby, MD on August 22, 2023
Vitamin D

Vitamin D


It helps keep your bones strong. People who have healthy levels of it may be less likely to get certain conditions, but more research is needed. Your body makes vitamin D when you’re in sunshine. It’s also in salmon, tuna, and fortified foods. If you’re low on vitamin D, your doctor may suggest a supplement. But several large studies show no benefits to otherwise healthy adults. And taking too much is bad for you.




Also called “good” bacteria, probiotics are found in fermented foods like yogurt, kombucha, miso, and sauerkraut. They can change the balance of good and bad bacteria in your body and may help improve digestion, soothe skin irritation, lower cholesterol, support your immune system, and more. But it’s not yet clear if probiotics in supplements help treat conditions, and most people don’t need to take them every day.   




If you know your diet isn’t that healthy, can a multivitamin help you fill in the nutritional gaps? Not necessarily. Many studies have found that multivitamins don’t fight memory loss, heart disease, or cancer. Meanwhile, getting too many nutrients in pill form can cause harm. Experts usually recommend food as the best source for vitamins and minerals.

Folic Acid

Folic Acid


Here’s a vitamin you definitely want to make sure you have enough of if you’re a woman who’s planning to get pregnant. Getting enough folic acid can help prevent birth defects in a baby’s brain and spine. You need 400 micrograms (mcg) per day, and the CDC recommends taking that much in a supplement, along with whatever you get from your diet.  

Fiber Supplements

Fiber Supplements


Fiber is in veggies, fruits, whole grains, seeds, nuts, and legumes like beans. It helps cut cholesterol, control blood sugar, and improve digestion. Women under 50 should get 25 grams a day, and men should get 38 grams. But only 5-9% of us hit those numbers. Taking a fiber supplement is usually safe, but ask your doctor, especially if you take medicines like aspirin. Start slowly to avoid gas and bloating, and be sure to get enough water.

Fish Oil

Fish Oil


Fish like salmon and sardines have healthy fats called omega-3s that can lower your risk of heart disease. If you don’t eat fish, there are fish oil supplements with omega-3s, like EPA and DHA, and there are algae-based supplements. But more research is needed, because omega-3s in pills may work differently than the ones in fish. If you take a pill, the FDA says to keep the dosage to less than 2 grams per day of EPA and DHA combined. 




Unless your doctor recommends it, you probably don’t need a calcium supplement. Some research has linked them to a greater risk of heart disease and prostate cancer, but that link isn’t clear. You can strengthen your bones with exercise like walking, tennis, dancing, and lifting weights. And fill your plate with calcium-rich foods like yogurt, almonds, dark leafy greens (for vitamin K), and fish or fortified foods for vitamin D.

Joint Supplements

Joint Supplements


Glucosamine and chondroitin, two types of arthritis supplements, are among the most popular supplements sold in the U.S. They are found naturally in human cartilage. Research on whether they can ease arthritis pain or prevent arthritis is mixed. Still, most experts say there’s no harm in trying them, in case you’re one of the people who gets relief from them. As with all supplements, it’s best to check with your doctor first.

Vitamin C

Vitamin C


Your body can’t make vitamin C, so you have to get it from food. And it’s easy to hit the recommended daily amount. Just 3/4 cup of orange or half a cup red bell pepper both provide more than 150% of what you need. So you probably don’t need a supplement. There are popular products on the market with mega-doses of vitamin C that claim to prevent colds (or at least shorten how long they last), but research on that has been inconclusive.




This hormone plays a role in sleep. Your body makes it, and it’s sold in pill form. Because there’s not much evidence about the safety of taking melatonin long-term, you’re better off trying it for short-term problems, like jet lag or a temporary bout of insomnia. Side effects can include drowsiness, headache, dizziness, or nausea.




This mineral supports your body in lots of ways. It gives you energy and keeps your heart healthy, for example. But even though it’s found in a range of foods, including nuts, seeds, whole grains, and leafy greens, most Americans don’t get enough. If you’re interested in taking a magnesium supplement, ask your doctor which type is best. There are several options.

Coenzyme Q10 (CoQ10)

Coenzyme Q10 (CoQ10)


This is an antioxidant your body makes, and you can get more of it in pill form. People try to use CoQ10 to fight migraines, protect the heart, and improve symptoms of Parkinson’s disease. But the research on whether it works is limited and conflicting. Side effects include insomnia and upset stomach, but they’re usually very mild. CoQ10 can interact with blood thinners and insulin treatments, so check with your doctor before taking it.




This yellow-orange spice may help tame inflammation, which is part of a wide variety of conditions. It’s not yet clear if turmeric thwarts any particular health problems. As a supplement, it’s sometimes labeled as curcumin, which is one of the active ingredients in turmeric that has been the focus of scientific studies. Up to 8 grams per day is considered safe. And it’s fine to add the spice to your foods.

Vitamin B12

Vitamin B12


You need it to make red blood cells and DNA and to keep your nervous system healthy. It’s found in animal products like fish, meat, eggs, and milk, so vegetarians and vegans may come up short, as can adults over the age of 50 and people with digestive problems like Crohn’s disease. B12 supplements are sold as pills or shots. B12 shots have become trendy as a way to try to boost energy and slim down, though no research shows they work.

Keep in Mind

Keep in Mind


Everyone is different. If you have a specific health concern that you think supplements might help with, ask your doctor. Your doctor can check to see what’s safe for you, tell you about potential side effects, and add your supplements to your health record. The FDA doesn’t approve supplements, unlike prescription drugs. So do your research and talk with your doctor first. 

Show Sources


1) Choreograph / Getty Images

2) Clockwise from top left:  trumzz / Getty Images, GreenArtPhotography / Getty Images, taa22 / Getty Images, zeleno / Getty Images

3) Lecic / Getty Images

4) Sam Edwards / Getty Images

5) marilyna / Getty Images

6) margouillatphotos / Getty Images

7) imtmphoto / Getty Images

8) Farion_O / Getty Images

9) Left to right:  YelenaYemchuk / Getty Images, AlexPro9500 / Getty Images

10) Weedezign / Getty Images

11) Clockwise from top left:  gontabunta / Thinkstock, bhofack2 / Getty Images, egal / Getty Images, Lecic / Getty Images

12) janulla / Getty Images

13) AD077 / Getty Images

14) AlexPro9500 / Getty Images

15) estherpoon / Getty Images



National Institutes of Health Office of Dietary Supplements: “Vitamin D,” “Probiotics,” “Multivitamin/mineral Supplements,” “Omega-3 Fatty Acids,” “Vitamin C,” “Magnesium,” “Vitamin B12.”

BMC Public Health: "Vitamin D levels and deficiency with different occupations: a systematic review."

The New England Journal of Medicine: "Vitamin D Deficiency -- Is There Really a Pandemic?" "Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease," "Vitamin D Supplementation and Prevention of Type 2 Diabetes."  

Harvard Health Publishing: “Vitamin D: What’s the “right” level?” “Should you take probiotics?” “Fish oil: friend or foe?” “What you need to know about calcium,” “The latest on glucosamine/chondroitin supplements,” “By the way, doctor: What's the right amount of vitamin C for me?” “Vitamin B12 deficiency can be sneaky, harmful.”

JAMA Cardiology: "Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 83 000 Individuals in 21 Randomized Clinical Trials."

The American Journal of Clinical Nutrition: "Randomized controlled trial of vitamin D supplementation in older people to optimize bone health."

The Lancet: "Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis."

Journal of the American Medical Association: "Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial."

The University of Texas MD Anderson Cancer Center: “Should you take a daily probiotic supplement?”

Annals of Internal Medicine: "Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements," "Association Among Dietary Supplement Use, Nutrient Intake, and Mortality Among U.S. Adults: A Cohort Study," "Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality."

Mayo Clinic: “Nutrition and healthy eating,” “Coenzyme Q10,” “Mayo Clinic Minute: Are there health benefits to taking turmeric?” “Are vitamin B-12 injections helpful for weight loss?”

Journal of the American Association of Nurse Practitioners: "Fiber supplements and clinically proven health benefits: How to recognize and recommend an effective fiber therapy."

MedlinePlus: “Dietary Fiber.”

American Heart Association: “Fish and Omega-3 Fatty Acids.”

National Institutes of Health National Center for Complementary and Integrative Health: “Omega-3 Supplements: In Depth,” “Melatonin: In Depth,” “Coenzyme Q10,” “Turmeric.”

Johns Hopkins Medicine: “Calcium Supplements: Should You Take Them?” “Melatonin for Sleep: Does It Work?”

National Institutes of Health Osteoporosis and Related Bone Diseases National Research Center: “Exercise for Your Bone Health.”

American Academy of Family Physicians: “Glucosamine.”

Arthritis Foundation: “Chondroitin Sulfate and Glucosamine Supplements in Osteoarthritis.”

Journal of the American Medical Directors Association: "Clinical Use of Curcumin in Depression: A Meta-Analysis."

Acta Medica Indonesiana: "The effect of curcumin on lipid level in patients with acute coronary syndrome."

National Center for Complementary and Integrative Health: “Melatonin: In Depth,” “5 Tips: What Consumers Need to Know About Dietary Supplements.”