Ask Dr. Shilpa: What Not to Take Together: The Supplement Combinations No One Talks About
Supplement routines are getting more stacked than ever, but more doesn’t always mean better. In fact, some of the combinations people rely on most could be working against them, competing for absorption or never fully being utilized by the body.
For this edition of Ask Dr. Shilpa, we tapped Dr. Shilpa Raut, Vice President of Research and Development at Cymbiotika, to break down what’s really happening behind the scenes of your supplement stack. From nutrient competition to absorption pitfalls, she explains why how you take your supplements matters just as much as what you take.
From a formulation and absorption standpoint, how real is the issue of supplement interactions?
Very real and often underestimated!
In the body, nutrients rely on specific transporters, enzymes, and pathways for absorption. When multiple nutrients are taken together, they can compete for the same transporters, alter pH or solubility, impacting absorption and influence metabolism in the liver. For example, a study in the American Journal of Clinical Nutrition showed that high-dose zinc reduces copper absorption due to shared intestinal transporters, whereas calcium can reduce iron absorption by ~30–50% when taken together in certain forms.
Another important factor to consider is that most nutrients are often either water-soluble or fat-soluble and need the right environment for optimal absorption. For example, vitamin D and omega-3s are fat-soluble and require a fatty meal or lipid-based delivery system for better absorption. Whereas it's best to take glutathione on an empty stomach. When you take a supplement that offers, say, 20 to 60 nutrients at once, it may sound convenient but most likely this reduces efficiency and increases the likelihood that a significant portion is not absorbed. It's only a waste of your money.
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