Walking into a drugstore, the shelves of supplements can be overwhelming. But what really determines effectiveness is often not which bottle you buy but whether you take it at the right time, in the right combinations, and for long enough. Below are the five things dietitians most often remind patients of.
1. Take fat-soluble ingredients with a meal
Fish oil, lutein, vitamin D, CoQ10 and other fat-soluble ingredients require dietary fats to aid absorption. Studies show that taking fish oil with a meal can increase absorption by several times compared with taking it on an empty stomach. By contrast, probiotics and collagen peptides are better taken on an empty stomach or before bed.
2. Don’t take all supplements at the same time
Calcium and iron compete for absorption, and high-dose zinc can affect copper metabolism. It’s recommended to spread mineral supplements across different meals and space them 1–2 hours apart from other ingredients.
3. Continue supplementation for at least 8 weeks
Supplements are not painkillers and won’t work instantly. Most ingredients need time to accumulate in the body — for example, lutein typically requires about 8 weeks and collagen about 12 weeks before effects become noticeable.
4. Check the "effective dosage"
A product labeled "contains lutein" might provide 3mg or 20mg. When choosing a product, confirm the amount per serving (recommended daily amount) rather than per capsule, and avoid products that are far below research-backed effective doses.
5. Consult first if you take medications for chronic conditions
Interactions can occur — for example, fish oil with anticoagulants, or ginseng with glucose-lowering drugs. If you are taking medication, be sure to bring a list of your supplements to your physician or pharmacist for evaluation.
Supplements are intended to "fill nutritional gaps", not to "replace meals or medications". A balanced diet, regular routines, and appropriate exercise remain the foundation of health.
