Vitamins and Supplements Are More Popular Than Ever, But Do They Actually Work? (2025)

While most people get enough nutrients from their diet, there are factors that can interfere with some people getting the nutrition they need. These include health conditions, medications taken, and the quality of the diet.

When you're lacking in certain nutrients, taking vitamins and supplements can bridge the gap to help ensure you are getting what your body needs. Knowing the right products to take and how to take them can ensure you get what your body needs to support your well-being.

When They Work

Vitamins and supplements work when taken as directed in the dosage advised by your healthcare provider or the manufacturer's labeling.

These products work best when you follow these guidelines:

• Take quality vitamins and supplements: Opt for supplements that display a seal from a trusted third-party organization.
• Follow label directions for storing products: When stored in cool, dry, and dark conditions, vitamins and supplements can retain 90% of their potency for five years or longer past theirexpiration date.
• Track your symptoms and their severity: Log everything in a symptom journal to monitor your results. This can help you work with your healthcare provider to modify your vitamin regimen for the best results.
• Take vitamins based on deficiencies: Vitamins work best when they are supplementing a vitamin deficiency identified by a blood test evaluated by your healthcare provider.

When They May Not Work

Many factors can impact the way vitamins and supplements work and the benefits you gain from taking them.

Vitamins may not work under the following circumstances:

• The product may be poorly manufactured: If this is the case, it may not contain the amount of nutrients indicated on the label.
• You may not be taking the supplement at the correct time: For maximum absorption, some supplements need to be taken at specific times of the day or with certain foods. For example, fat-soluble vitamins, which include vitamins A, D, E, and K, are absorbed better if they are taken with a meal that contains fats.
• Taking too many supplements: You may be taking large doses of calcium or another mineral at the same time as other nutrients, thereby reducing the absorption of the lower-dose nutrients.
• Medications interfere with supplements: You may be taking certain medications that interfere with your ability to absorb and utilize nutrients.
• You may have malabsorption syndrome: This can happen as a result of damage to your small intestine that interferes with your ability to absorb nutrients.
• You haven't been taking them long enough: You may not have been taking the vitamins or supplements long enough to improve symptoms. Water-soluble vitamins, including vitamin C and all the B vitamins, are more easily absorbed and may provide faster results than fat-soluble vitamins that require fat for optimal absorption.
• They are past their effective date: You may be taking vitamins and supplements that are less effective because they are past their effective date.
  

Who Might Benefit From Using Vitamins & Supplements

You might benefit from using vitamins and supplements if you are not getting certain vitamins or supplements through your diet or the nutrients you do get may be affected by health problems, medications you take, or other uncontrollable factors. People who may benefit from supplements include:

• Pregnant people: Folic acid supplements can reduce the risk of neural tube defects such as spina bifida.
• People on restricted diets: Vegans and people with celiac disease may benefit from a multivitamin with iron, vitamin D, copper, zinc, and B12. People who avoid certain food groups due to lifestyle or food allergies may benefit from supplements to replace the nutrients they're missing from foods.
• People with certain health problems: People with osteoporosis may benefit from calcium and vitamin D. People with conditions such as heart disease, cancer, diabetes, human immunodeficiency virus (HIV) or AIDS, and some autoimmune diseases may benefit from certain vitamins and minerals.
• Older adults: Older adults may benefit from vitamin D, vitamin B12, and calcium supplementation since the ability to absorb and process these nutrients declines with age. People with AMD or at risk of the disease may benefit from vitamin A, which can slow down the vision loss associated with this condition.

Risks of Overusing Vitamins and Supplements

While nutrient deficiencies can cause a wide range of health problems, it's also possible to risk serious side effects by using more than the recommended dietary allowance (RDA) of certain vitamins and supplements.

Vitamin toxicity occurs when you overuse certain vitamins and supplements. This results in taking more than your body needs to keep it healthy. Side effects can vary based on your overall condition and the specific vitamin or supplement overused. Some common symptoms include:

• Vomiting
• Diarrhea
• Fatigue
• Bone pain
• Joint pain
• Muscle pain or weakness
• Skin problems
• Liver damage
• Frequent urination
• Cloudy urine
• Irregular heartbeat
• Stomach pain

The risks of overusing certain vitamins and supplements over long periods can result in long-lasting and severe problems, such as

• Vitamin A overuse: Can cause headaches and liver damage, reduce bone strength, increase birth defects, and increase the risk of cancer in smokers.
• Iron overuse: Can cause nausea, vomiting, and damage to your liver and other organs.
• Vitamins B6 and B12 overuse: Can cause an increased hip fracture risk among postmenopausal women.
• Vitamin D overuse: Can cause high levels of calcium in your blood.
• Vitamin K overuse: Can negatively impact the efficacy of some blood thinners such as Coumadin (warfarin).
  

Choosing High-Quality Supplements

Choosing high-quality supplements requires considering the following characteristics to ensure you're getting the safest products possible:

• Look for products with a seal of approval from a third-party testing organization: Organizations such as U.S. Pharmacopeia (USP), ConsumerLab.com, or NSF.org verify that the product was tested and found to be manufactured properly.
• Select supplements manufactured by reputable store brands or nationally recognized brands: Respectable businesses offer products formulated to align with scientific research. With their reputations on the line, these companies are more likely to use higher-quality ingredients that deliver as expected.
• Beware of claims in advertising and on product labels: The manufacturers of vitamins and supplements can't claim that their product can prevent, diagnose, treat, or cure diseases. They can only make three types of claims on product labels or in advertising.
• Pay attention to ingredients listed as "other" or "inactive" ingredients: Supplement manufacturers are required to identify all inactive ingredients in addition to active ingredients. You can often find these ingredients, which include binders, fillers, flavorings, and colorings, in the small print at the bottom of a label.
  
• Consult your healthcare provider before consuming any new vitamin or supplement: Your healthcare provider can help you identify quality supplements that are the safest and most effective option for your needs.
  

Summary

While vitamins and supplements can help bridge gaps in your nutritional needs, they can't replace a healthy diet. Research shows that eating whole foods is always the best way to obtain the nutrients your body needs.

Though they can be purchased over the counter, vitamins and supplements are not always safe. Taking nutrients in higher than advised doses or with certain drugs can alter the way they affect your body. It can also increase your risk of adverse effects.

Contact your healthcare provider before you begin taking any new vitamin or supplement. They can help you determine what you require and the best way to meet your nutritional needs safely and effectively.