Walk through a pharmacy or spend a few minutes online and you could come away thinking there is a supplement for every concern. Better sleep, stronger immunity, younger skin, improved metabolism: the claims are endless.
I have a simpler question when a patient brings me a new bottle: What are we hoping this will accomplish, and what is the evidence that it will help you?
A supplement can be useful when there is a clear reason to take it. It can also create unnecessary expense, interact with medication, or cause harm.
Start with the reason, not the trend
Consider vitamin D. Supplementation may be appropriate for someone with a deficiency or a particular risk factor, but that does not mean everyone needs a high dose. The same principle applies to iron, vitamin B12, and other nutrients.
Protein supplements can sometimes help people meet their nutritional needs, especially when food intake is limited or protein requirements are higher. They are a convenience, not a replacement for a balanced diet.
Omega-3 products, magnesium, collagen, and probiotics are frequently marketed for broad benefits. In reality, evidence depends on the specific product, dose, condition, and person. For example, benefits demonstrated for a particular probiotic strain should not be assumed to apply to every product labeled “probiotic.”
More is not always better
A few examples illustrate why I ask patients to review their supplements as carefully as their medications:
- Zinc: Long-term high doses can interfere with copper balance.
- Magnesium: Some forms cause diarrhea, and supplemental magnesium can be unsafe for people with significant kidney impairment.
- Herbal products: Certain ingredients can interact with prescription medicines or affect how they work.
- Multiple overlapping products: A multivitamin, a greens powder, and a “longevity blend” may contain some of the same nutrients, making the total dose easy to overlook.
“Natural” does not automatically mean safe. Nor does an impressive ingredient list mean a product has been tested for the outcome advertised.
Quality matters, but quality is not proof of benefit
Independent testing programs can offer reassurance that a product contains what its label claims and meets certain quality standards. That is useful, but it is different from demonstrating that the product will improve your health.
I encourage patients to keep an up-to-date list of everything they take, including dose and frequency, and to share it with their clinicians. This is particularly important before surgery, during pregnancy, and when taking prescription medications.
Three questions worth asking
Before adding a new supplement, consider:
- What specific problem am I trying to address?
- Is there reliable evidence for this product, in someone with my circumstances?
- What are the potential interactions, side effects, and reasons to stop?
If there is no clear answer, it may be better to wait and have a conversation first.
The goal is not to take more supplements. It is to make thoughtful decisions about the few, if any, that serve a clear purpose.
