It's easy to end up taking the same nutrient twice without noticing. A multivitamin, a specific product bought for another reason, and a fortified food or drink can all contribute to the same nutrient — and the totals add up.
Where this shows up most often
Zinc, magnesium and vitamin D are common examples: all three appear in general multivitamins and in a wide range of targeted products (immune support, sleep, bone health, and others), which makes it straightforward to combine two or more without intending to.
How to check
- List every supplement you're currently taking and note each one's dose table.
- Add up the % NRV for any nutrient that appears in more than one product.
- If the combined total looks high, or you're not sure what a safe upper limit looks like for that nutrient, that's a question for a GP or pharmacist rather than a guess.
Overlap isn't automatically a problem — plenty of nutrients have wide safety margins. But knowing the combined total is the only way to actually judge that, rather than assuming each product is being taken in isolation.