The vitamin and supplement industry is a billion-dollar industry in the U.S. More than half of all Americans report taking one or more dietary supplements on a daily basis, with those 65 and older accounting for 70 percent of that number.

But are vitamins and supplements really necessary for overall health? Are they safe? And do they really work?

Dietary supplements 101
Vitamins and supplements are available over-the-counter and without a prescription, and are easy to find at most drugstores and big box stores as well as online. There are even specialty stores that only sell dietary supplements and related products.

Most dietary supplements come in pill or capsule form but some are also available as a liquid or powder. More recently, gummies have become popular for some types, especially for vitamins and probiotics. In addition to well-known products like multivitamins, other common supplements include specific vitamins, minerals, probiotics, enzymes, and herbal products, also called botanicals.

There are several different types of dietary supplements:

Vitamins – Our bodies need essential nutrients found in vitamins to function healthfully and properly. Vitamins are either fat-soluble or water-soluble. The difference between the two types determines how each vitamin acts within the body. Fat-soluble vitamins dissolve in fat and are stored in your body. Fat-soluble vitamins include vitamins A, D, E, and K. Water-soluble vitamins dissolve in water and are carried to the body’s tissues but are not stored. Water-soluble vitamins include vitamins C and B.

Minerals – Minerals are elements found on the earth and in foods that are essential for specific bodily functions such as growth, bone health, and fluid balance. Examples of minerals that are crucial for health include calcium, potassium, sodium, chloride, magnesium, iron, and zinc, to name a few.

Proprietary blends – Some dietary supplements contain a combination of ingredients. However, it is not always clear how much of each ingredient the blend contains, so products vary greatly.

Are supplements necessary?
Most people who take dietary supplements do so to ensure that they are getting enough essential nutrients and to improve their health. But not everyone needs to take supplements. If you eat a variety of healthy foods daily, you are more than likely already getting all of the nutrients your body needs, so you don’t need to take a supplement.

There are some instances where particular supplements can be helpful in filling in the gaps in your diet. Or if you are on a restricted diet or have certain medical conditions, taking vitamins and supplements may be useful. If you decide to take any dietary supplement, even something as common as a multivitamin, always speak with your doctor first. Some supplements can have negative effects with certain health conditions or may interact with other medications, so it’s best to exercise caution and always consult your physician.

Just like prescription medications, some supplements may also cause side effects. Everyone’s body chemistry is different, so a product may affect you differently than someone else. Supplements have not been tested in children, pregnant, or nursing women, and some other groups.

The skinny on supplements
Dietary supplements are regulated by the FDA as food, not as drugs, so they are not tested for safety or effectiveness. While many supplements claim to offer specific health benefits, they cannot legally claim to cure, treat, or prevent a disease, unlike medications that are FDA-regulated. Just because a supplement is touted as “safe” does not mean it is safe.

If you decide to take any dietary supplements, your expectations should be realistic as far as their effectiveness. No dietary supplement can reverse or cure a disease. Supplements also cannot induce weight loss, and some products marketed as weight loss-enhancing supplements can contain potentially dangerous ingredients.

But there are some supplements that may enhance health in different ways. For example, some of the most popular supplements are multivitamins, calcium, and vitamins B, C, and D. Calcium can support bone health, especially as you age, and if you don’t regularly drink milk or consume other dairy products, a calcium supplement can help your body get that essential nutrient. Vitamin D helps the body absorb calcium, and many people are low on this important vitamin, so a supplement may be helpful. Your doctor can perform a test to determine your vitamin D levels to see if you’d benefit from supplementation.

During pregnancy, women need additional iron and folic acid, so supplements are usually recommended. Vitamin B12 keeps nerves and blood cells healthy and functioning properly, and is found mostly in meat, fish, and dairy foods. So if you are vegan or vegetarian, taking a B12 supplement may be beneficial.

Choosing the right supplements
The variety of vitamins and supplements on the market can be overwhelming, and because they are not FDA-regulated, it can sometimes be hard to know what’s safe to take. To find reliable information on supplements, the National Institutes of Health (NIH) has a fact sheet available at ods.od.nih.gov/factsheets/list-all/. NIH also has a free Dietary Supplement Label Database at www.dsld.nlm.nih.gov where you can look up the ingredients of thousands of dietary supplements. It includes information on dosage, health claims, and warnings.