5 Supplement Myths That Might Be Costing You Money

Nearly three in five American adults now take at least one dietary supplement, fueling a $60-billion-a-year market of products that often offer no scientifically proven benefit. Stanford Medicine nutrition experts are debunking five costly myths that might be influencing your supplement choices.

Do Most People Actually Need Supplements?

The biggest misconception is that everyone should take supplements. According to Marily Oppezzo, instructor of medicine at the Stanford Prevention Research Center, and Catherine Hu, a clinical dietitian in endocrinology, supplements typically make sense only for those with a proven deficiency, restricted diet, or specific condition known to benefit from them.

Getting blood tests through a medical provider can reveal whether you're clinically deficient in certain vitamins or minerals. However, blood labs don't provide a complete nutritional picture since we don't store most nutrients in the serum.

• Vegans: Should take vitamin B12, typically found in animal products, and consider calcium, zinc, iron, and vitamin D
• People over 50: May need extra calcium, vitamin D, and vitamin B12 to promote bone and nerve health
• Pregnant women: Should take prenatal vitamins containing folic acid and omega-3 fatty acids
• Bariatric surgery patients: Likely need additional nutrients because they're eating less

Why 'Natural' Doesn't Always Mean Safe?

The Food and Drug Administration regulates supplements as food, not drugs, so it doesn't verify their safety, effectiveness, or contents before they're sold. This means purity and dosage can vary widely between products.

Some turmeric pills have been found to contain high doses of heavy metals, while spirulina and chlorella tablets can include mycotoxins. The experts recommend choosing supplements verified by independent groups like US Pharmacopeia, NSF, or Consumer Lab.

"I would always recommend speaking with your medical provider and letting them know what supplements you're taking," said Hu. "They can confirm based on your medications, and the disease or chronic condition you have, whether it's safe."

Can You Skip Healthy Eating If You Take Supplements?

Evidence suggests many nutrients are better absorbed from foods than from supplements. Heat processing to make supplements shelf-stable can make them less potent. "If you take a special compound out of broccoli and put it in a powder, it's not going to have the same effect as the whole plant did," explained Oppezzo.

There's stronger evidence that fermented foods like yogurt, kefir, and kimchi improve gut health than there is for probiotics. Even people taking supplements should maintain a balanced diet focused on whole foods and variety.

Higher doses don't necessarily lead to better results and can sometimes backfire. Too much vitamin B6 can damage nerves, high doses of omega-3s can trigger irregular heartbeat in some people, and excessive vitamin D may increase fracture risk.

For many popular supplements, proof of effectiveness is lacking. Studies show melatonin shortens the time it takes to fall asleep by an average of only four minutes. "The effect size is so small, why don't you spend your time and money on something else?" asked Oppezzo.

Some people refer to unnecessary supplementation as having "very expensive urine," since the body simply excretes what it can't use. The key is focusing on proven deficiencies rather than hoping supplements can fix everything.