It’s common to take supplements — i.e., products taken orally to supplement the diet — at the request of your healthcare provider, especially if you’re deficient or have a specific medical condition.
However, supplement use in otherwise healthy individuals has gained in popularity over the years. In a 2021 report, 57.6% of U.S. adults over the age of 20 had used at least one dietary supplement in the past 30 days . Seniors over the age of 60 were most likely to be taking supplements.
While often benign, the unregulated nature of the dietary supplement industry can make these products tricky to navigate — and even lead to unintended health consequences.
A look into the vitamin and supplement industry
The vitamin and supplement industry is projected to reach nearly $40 billion this year . By 2025, the industry is estimated to reach nearly $60 billion in the U.S. and nearly $200 billion worldwide .
Dietary supplements may include:
- Vitamins (vitamin A, C, or a multivitamin) and minerals (magnesium, calcium, etc.)
- Protein powders (collagen, whey, pea protein)
- Compounds (curcumin, resveratrol, caffeine)
- Herbals and botanicals (ginger, gingko, etc.)
Are vitamins regulated by the FDA?
The short answer? No.
The U.S. Food and Drug Administration (FDA) regulates dietary supplements differently than conventional foods and drugs.
While drugs go through a rigorous and often years-long FDA approval process before entering the market, dietary supplements, on the other hand, do not undergo this process and are considered safe until proven otherwise .
The Dietary Supplement Health and Education Act (DSHEA) provided a regulatory framework for the safety and labeling of dietary supplements in 1994 . Under DSHEA, manufacturers and distributors are responsible for self-determining that their product is safe — and that any claims made are evidence-based to prove that they are not misleading or false. Additionally, they don’t have to provide the FDA with any evidence they are supposedly relying on to support these claims or the safety before or after the product hits the market.
Put another way, the dietary supplement industry is self-regulated and does not have to show any proof that these products are safe or that the claims are true before being available for purchase to the public.
The lack of regulation for supplement brands leads to many consequences, such as severe safety issues, manufacturing violations, and improper marketing or misbranding (i.e., the use of prohibited disease claims) . Unethical individuals and companies continue to manufacture and distribute low-quality, corrupted, or misbranded products labeled as dietary supplements.
This is not to say that all dietary supplements are bad or that you should avoid them. However, it’s important to be aware of these issues and be cautious of the brands you’re buying your products from.
Are vitamins and supplements good for you?
Adding a scoop of greens powder to your daily smoothie has become trendy, but is it actually beneficial for your health? Do you need to take that multivitamin gummy each morning — or do you take it because the label claims that it helps support “bone health, immune health, and energy metabolism”?
If you eat a balanced diet that contains a variety of vegetables, lean protein, healthy fats, and complex carbohydrates, then you probably don’t need the addition of a supplement.
However, there are certain cases — like following a strict diet (i.e., vegetarians/vegans) or having a certain condition (i.e., chronic gastrointestinal disease) — that prevents the absorption of certain vitamins and minerals where a dietary supplement may be crucial for your health. There’s no one size fits all approach when it comes to dietary supplements.
If you are taking dietary supplements, then they should be just that — a support or addition to your diet, not a cure-all approach. Not everyone needs to take them and some supplements either don’t add any benefit or even worse, could be doing more harm than good.
Can you take too much of a supplement?
Dietary supplements are beneficial when they are filling a void that you have in your body. However, without proper education or monitoring of your intake and blood levels, you could end up doing more harm than good to your health and your wallet.
It’s possible to take too much of a vitamin or supplement. The National Academies of Sciences, Engineering, and Medicine (NASEM) recommend specific intake amounts for optimal health, and to prevent toxicity or risk due to chronic overconsumption.
These dietary recommendations are referred to as dietary recommended intakes (DRIs). The highest average daily nutrient intake level that is likely safe for almost everyone to consume is the tolerable upper intake (TUI).
It’s easy to supplement with too much of a vitamin or mineral if you’re not aware of the appropriate dose or what the dose is. When you surpass the TUI for a given nutrient, you put yourself at risk for undesired side effects — such as nausea, GI distress, and (in more severe cases) even seizures or death.
The most common supplements that can cause harm if you take too much of them for a given time period include vitamins A, D, E, C, B6, and B12 .
To properly take supplements, you need to be familiar with research on safe dosages, how different vitamins/minerals potentially interact with one another, and how brands are manufacturing their supplements. You could be throwing money out the window as you're buying random supplements that you believe you need due to false claims or trends.
The bioavailability of supplements
Taking too much of a supplement is one problem, but you can also take a supplement that your body isn’t even absorbing.
Bioavailability is the amount of a nutrient in food that is absorbed and available for metabolic processes in the body. Many factors influence bioavailability — including the source, storage conditions, processing, preparation, mastication (i.e., whether you’re swallowing a capsule, chewing a tablet, etc.), and digestion .
Let’s look at the micronutrient iron as an example. There are two forms of dietary iron: heme and non-heme . Heme iron is found in animal foods, while non-heme iron is the only form of iron in plant foods and some in animal foods. Non-heme iron is also in enriched and fortified foods and dietary supplements.
Why does this matter? As it turns out, heme iron is more bioavailable than non-heme iron. This means that you will get more iron from an animal-based food source such as chicken compared to taking an iron supplement.
Benefits of dietary supplements — and which to take
People take supplements for various reasons:
- Deficiencies due to inadequate food intake, poor access to food, or strict dietary patterns (i.e., vegan or vegetarian)
- Inadequate bioavailability of nutrients
- Life stages such as pregnancy or older age
- Diseases like intestinal parasites or chronic gastrointestinal conditions
In situations like these, supplements can certainly work — especially when taken consistently and for an adequate amount of time. That said, if you’re taking supplements, you should get your blood work and status checked regularly by your healthcare provider to determine whether you need to continue supplementing.
Supplements do not cancel out or offset the metabolic consequences of eating foods high in sugar or processed foods.
And taking supplements should not be a replacement for getting nutrients from whole foods and a balanced diet rich in colorful vegetables, lean proteins, and healthy fats.
Whole foods contain an important nutrient — fiber — which supplements lack. Dietary fiber is naturally found in fruits, vegetables, whole grains, nuts, seeds, and legumes. Fiber helps to support the digestive and immune systems, makes you feel full after meals, keeps your energy levels high, supports your microbiome, and balances blood sugar levels.
Whole foods are also unprocessed and may provide more nutrients for your body, since heating and processing can actually destroy some of the beneficial compounds in foods.
Ultimately, if you’re monitoring your blood levels and you’re not at risk of reaching toxic levels, then supplements don’t hurt. However, you’ll get way more bang for your buck if you focus on getting these vitamins and minerals from whole food sources instead of spending money on trendy, expensive supplements.
Dietary supplement use has been increasing worldwide, but the industry itself is largely unregulated, with little oversight from the FDA.
For most people, eating a diet that’s rich in whole, unprocessed foods — including vegetables, healthy fats, and lean protein — is enough to meet your daily micronutrient needs, but the best way to know if you’re deficient is to get a blood test.
If you’re lacking in a particular vitamin or mineral, try to close to the gap with foods before you supplement. This doesn’t always mean vastly changing your diet — here are some ways to incorporate nutrient-rich fruits and vegetables:
- Blend whole leafy greens into soups, smoothies, sauces, or dressings.
- Add sauteed whole or pickled vegetables to pasta, egg scramble, or sandwiches.
- Meal prep vegetables and fruit by cleaning and cutting them up and sticking them in your refrigerator for an easy snack.
- Roast your favorite vegetables to have as a side or snack throughout the week.
If you still need to supplement to meet your daily needs (i.e., you’re vegan, have an autoimmune condition, etc.), here are some tips to choose the best supplements:
- Buy targeted, single-ingredient products (like vitamin A, calcium, etc.) rather than blends or multivitamins, which can lead to over-supplementation.
- Look out for third-party seals — such as GMP or NSF — that hold supplements to specific compliance standards and involve routine facility inspections.
- Some supplements, like fish oil, are particularly prone to mercury or heavy metal contamination — check this database to see mercury and potency information on the most popular fish oil supplements .
- Check whether your supplement is fat soluble or water soluble, and make sure you’re eating fat-soluble vitamins with a food that contains fat, and water-soluble vitamins on an empty stomach .
- Research the best combinations of vitamins and minerals — for example, eat calcium with vitamin D to help your body absorb the calcium, and take vitamins A, D, and K together.