Key takeaways
- Most adults can meet their nutrient needs with food. Pregnancy, lactation, infancy, special diets, and diagnosed deficiencies are common reasons doctors may recommend supplements.
- Research-backed supplements in certain situations include prenatal vitamins with folic acid and iron, vitamin D when intake is low, and omega-3s, vitamin B12, iron, or magnesium when diet or labs show a deficiency.
- Green powders, probiotic supplements, and “mega-dose” products often lack strong support, and taking too much can cause side effects. Choose third-party-tested products, consider chelated minerals for better absorption, and check with your doctor about dosing and interactions.
Supplements are having a moment.
About 3 in 4 U.S. adults take some form of nutritional supplement, according to a 2022 survey. And just over half of supplement users take a specialty supplement, like omega-3s, probiotics, or fiber.
Johna Burdeos, RD, a registered dietitian, says a myriad of factors have contributed to the popularity of supplements, vitamins, and minerals, including the pandemic and ease of purchasing via online retailers.
Still, supplements aren’t without their detractors. The Food and Drug Administration (FDA) does not regulate supplements the way it does medications.
Plus, you may wonder whether you need dietary supplements if you’re eating a well-balanced diet.
Here’s what the research and experts have to say about when it’s beneficial to add vitamins, minerals, and supplements to your diet, plus which ones to choose.
The subject is up for debate, even among experts.
“Supplements are not usually the only possible solution for most adults to achieve and maintain good health,” says Maddie Pasquariello, MS, RDN. “In fact, for many of those experiencing health problems, supplements are not usually the first line of defense that dietitians will turn to.”
Other lifestyle tweaks, like changes to diet and exercise recommendations, typically come first.
That said, supplements are a recommended standard in some cases. In other cases, they may help fill nutrient gaps in the diet, says Stephanie Greunke, RD, a registered dietitian and member of Needed’s practitioner collective.
Common cases where providers will recommend taking vitamins, supplements, or minerals include:
- pregnancy
- lactation
- infants receiving human milk or less than 32 oz. per day of formula
- health improvement
- special diets
- deficiencies
Supplements may have their detractors, but some can be beneficial, particularly in specific circumstances.
Prenatal vitamin
The American College of Obstetricians and Gynecologists (ACOG) recommends people with uteruses should begin taking prenatal vitamins when they start trying to become pregnant and continue intake throughout pregnancy. Burdeos recommends starting 3 months in advance of your first attempt to become pregnant.
The
ACOG also recommends getting at least 27 milligrams of iron per day during pregnancy, something often found in prenatal vitamins.
Burdeos says folic acid combined with iron provides benefits for a fetus.
“Folic acid helps prevent neural tube defects, which are serious abnormalities in the baby’s brain and spinal cord,” Burdeos says. “Iron helps facilitate the transportation of oxygen throughout the body. Iron helps support the proper development of the baby and the placenta.”
Vitamin D
About 42% of people are vitamin D deficient, and Black people have the highest rates — 82%, according to a 2022 study.
The sun is a natural source of vitamin D, and egg yolks and fatty fish are quality food sources. Other than that, it’s slim pickings, according to the
“It’s nearly impossible to get all the vitamin D you need from food alone,” Greunke says. “Oily fish, mushrooms, and fortified dairy provide vitamin D, but not in sufficient quantities to meet daily needs.”
Vitamin D deficiency is linked to multiple conditions,
- reduced bone health
- cancer
- cardiovascular disease
- diabetes
- depression
Vitamin D supplements and pregnancy
ACOG and
Recent research is inconclusive as to whether vitamin D supplementation reduces the risk of pregnancy complications, though some previous studies suggest it might.
Infants up to 12 months need at least 400 international units (IU) of vitamin D per day, equivalent to 10 mcg.
Infant formula is fortified with vitamin D, so children who are formula-fed don’t usually need a supplement, according to the
People ages 1 to 70 need 600 IU (15 mcg) per day, and those over 70 need 800 IU (20 mcg) per day. Since it’s challenging to get that from food, Greunke says a vitamin D supplement is worth it, even past infancy.
Omega-3s
One of the most popular vitamins might be omega-3s. These are fatty acids naturally found in fish like salmon and nuts, such as walnuts.
Burdeos says that you may benefit from taking one if your diet is low on these items. Though omega-3s are linked with good heart health, the
However, the agency says it may help reduce triglycerides and soothe rheumatoid arthritis symptoms.
Vitamin B12 (cobalamin)
Vitamin B12 naturally occurs in animal products, and Burdeos says it’s important for:
- red blood cell formation
- DNA production
- nerve function
- cell metabolism
A 2022 study suggests that vitamin B12 deficiency is higher among pregnant people and those who follow a plant-based diet, such as vegan or vegetarian.
Burdeos says B12 supplementation is worth it for people who are deficient in the vitamin, particularly those who do not consume animal protein.
Iron
Iron is present in food like red meat, shellfish, and dark, leafy greens. It helps:
- carry oxygen from the lungs to the tissues
- bolster muscle metabolism
- support physical growth
- aid in neurological development
Though Pasquariello typically recommends a food-first approach, people with iron deficiencies and those who are borderline anemic may benefit from iron supplementation.
Additionally, pregnant people should seek out a prenatal with iron to support fetal development. Always ask your doctor for the best option, as taking too much iron can, in rare cases, lead to iron poisoning.
Magnesium
Magnesium is a naturally occurring mineral and the
Greunke says that magnesium supplements can help.
Research indicates oral magnesium supplementation may help:
- reduce blood pressure
- lengthen sleep duration
- reduce fasting and post-meal blood sugar levels
- improve mood
Some supplements, like probiotics, are all the rage. But experts and researchers say the data isn’t there to support the hype. You can hold off on trying these supplements.
Greens powders
These powders look healthy and have promising buzzwords on labels.
“Most greens powders products claim to be filled with whole food sources of nutrients and pre- and probiotics,” Pasquariello says. “This is highly deceptive, as it tricks consumers into thinking they can then substitute greens powders for actual greens or green vegetables.”
Pasquariello says claims that greens powders boost energy, performance, and digestion are unfounded.
There’s not much research on them, aside from a small
Pasquariello suggests adding actual greens, specifically the leafy variety, to your diet instead.
Probiotics
Probiotics are among the most popular supplements, but the
Mega-anything
Some products will market themselves as having “mega-doses.” The jargon sounds great, but Burdeos says it’s not.
“Unless it is specified by your doctor, these kinds of supplements are a case of too much of a good thing,” she says.
She says the mega-doses can have long-term impacts.
“For example, too much vitamin D can lead to kidney problems, and too much vitamin C can cause digestive issues,” Burdeos says.
This applies to taking any supplement at all. If you’re getting the nutrients from diet alone, there’s no need to add any more of it to your diet through an oral tablet or powder.
Buffered creatine monohydrate
Both Greunke and the
“These formulas are more expensive and state that they’re better absorbed, but that hasn’t proven to be true,” Greunke says.
Since supplements are not held to the same standard as food, it can feel like the Wild West out there. Experts share insights for navigating the vitamin and mineral aisle of the grocery store below.
Chelated vs. non-chelated
You may notice these terms on mineral bottles.
“Chelated means the mineral was altered in a way that improves absorption,” Greunke says. “This is done by combining the mineral with another molecule, like an amino acid or organic acid, to make it easier for the body to absorb.”
Examples include:
- iron bisglycinate
- zinc bisglycinate
- chromium picolinate
- and magnesium bisglycinate
“Non-chelated minerals, on the other hand, are unstable, and, as they aren’t bound to something else, they are attracting other molecules to bind to them, thus interfering more with absorption,” Burdeos says.
However, research as to which form is more effective is mixed and often includes small sample sizes.
Evaluating mineral sources
Greunke says food and water make up the majority of our mineral intake. They can also be found in:
- trace mineral drops
- salts
- electrolyte products
“Thoughtful supplements take into consideration nutrient competition,” Greunke says. “For example, iron competes with other minerals for absorption, such as zinc, calcium, copper, and magnesium.”
Greunke suggests avoiding multivitamins with iron. Calcium and iron supplements can be taken a couple of hours apart. It’s also possible to take too much iron, so always talk with a doctor before adding it to your supplement regimen.
Other important details when choosing supplements
The experts Healthline spoke with also recommended:
- ensuring third-party testing, such as through U.S. Pharmacopeial Convention and Consumer Labs
- avoiding artificial colors, flavors, and sweeteners
- avoiding fillers like stearic acid, silicon dioxide, and titanium dioxide
- choosing whatever works best for you when it comes to pills, chewables, gummies, or powders
- selecting only the supplements that fit your medical and dietary needs
- reading labels with a critical eye — if it sounds too good to be true, it probably is
Minerals and electrolytes
Some minerals are electrolytes — a subgroup of minerals that help:
- maintain fluid balance
- keep your heart beating normally
- aid in blood flow
- regulates blood pressure
- support bone health
- influence your hormones
- support adrenal health
You usually don’t need electrolyte supplements, but some people take them to replenish minerals lost through exercise, illness, or extreme heat. Key electrolytes include:
How do you know if your supplement is actually working or whether you should scale back? Experts share a few telltale signs.
Elimination
Much of what goes in eventually comes out.
“High doses of magnesium citrate and vitamin C can cause diarrhea, so if this is happening, you’ll want to reduce the amount you’re taking,” Greunke says. “Sometimes, high doses of B-vitamins can lead to bright yellow colored urine; however, this isn’t necessarily harmful.”
Your energy levels
Is the pep in your step the result of a supplement or a placebo effect?
“Some supplements like vitamin B12 can yield quick improvements in energy,” Greunke says. “Adrenal supplements can help individuals feel calmer and focused relatively quickly. If an individual is dehydrated or imbalanced in minerals, an electrolyte supplement can boost energy, physical performance, and improve blood pressure.”
Others may have more subtle or long-term effects.
OTC and in-office tests
Whether over-the-counter (OTC) or in-office testing is necessary depends on the reason you’re taking the supplements.
If it’s to lower blood sugar because of prediabetes or diabetes, at-home glucose monitoring and in-office bloodwork are important, Greunke says.
Pasquariello says medical professionals can also check your blood nutrient levels before you start taking a supplement and after you consume it for a specific period.
“If you’re just starting supplementation for the first time or using it to help improve certain symptoms, in-office tests can be helpful,” Pasquariello says. “If you’re experiencing side effects from a supplement, an in-office test can also be recommended.”
In general, Pasquariello says it’s always important to connect with your doctor about any supplements you’re taking to ensure they don’t interfere with any medications or treatments.
This depends on your needs. People who are pregnant or trying to get pregnant should take a daily prenatal.
Vitamin D may also reduce the risk of pregnancy complications like gestational diabetes. Infants who aren’t formula-fed need daily vitamin D, or the lactating parent can supplement with vitamin D.
Other potentially important supplements include magnesium, iron, and omega-3s, but always talk with a doctor before starting supplementation, especially when it comes to iron.
Discuss this with your doctor or a dietitian. The answer will depend on whether you are pregnant or lactating, your age, diet, and health needs.
Not all vegans and vegetarians require supplementation, but Pasquariello says B12 is the most common deficiency.
For those on the keto diet, Pasquariello suggests discussing vitamin D and calcium supplementation with your doctor.
Burdeos and Greunke say creatine monohydrate can help build muscle. The “buffered” kind is unnecessary and not supported by data.
Most experts don’t believe vitamins or supplements are necessary for weight loss. Instead, work with a healthcare professional or dietitian to meet your goals through sustainable diet and lifestyle tweaks.
Women don’t necessarily need special supplements, but experts say pregnant people should take prenatal vitamins with folate and iron. Ask your doctor for the best option for you.
Experts recommend that people begin taking prenatal vitamins 3 months before trying to become pregnant. Vitamin D supplementation during pregnancy may help protect against pregnancy complications, but the evidence is inconclusive.
Vitamins, minerals, and supplements are buzzy, but most people get enough nutrients from diet alone.
However, supplementation is sometimes necessary, such as during pregnancy or lactation.
It’s important to remember that the FDA doesn’t regulate the vitamin and supplement industry. Talk with a doctor about any supplements you’re considering to ensure they’re safe for you.
Beth Ann Mayer is a New York-based freelance writer and content strategist who specializes in health and parenting writing. Her work has been published in Parents, Shape, and Inside Lacrosse. She is a co-founder of digital content agency Lemonseed Creative and is a graduate of Syracuse University. You can connect with her on LinkedIn.