Are You Taking Several Supplements? Be Careful With These Combos!

1. Iron + Calcium

Calcium may inhibit the absorption of nonheme iron, potentially impacting those with iron deficiency. To maximize absorption, take iron and calcium supplements at different times of the day.

2. Zinc + Calcium

“Zinc and calcium compete for absorption in the gut, so taking them together can limit the effectiveness of both,” says Alyssa Simpson, RDN. To ensure proper absorption, take these supplements at least two hours apart.

3. Iron + Zinc

Iron supplements (especially those with 25 mg or more of iron) can interfere with zinc absorption. To avoid deficiencies, take them separately with a two-hour gap.

4. Magnesium + Zinc

Both minerals compete for absorption, and high doses of zinc (140 mg+) can significantly reduce magnesium uptake. To avoid this, take magnesium at night (it aids sleep) and zinc in the morning with food to prevent nausea.

5. Ginkgo Biloba + High-Dose Fish Oil

Both are natural blood thinners, increasing the risk of excessive bleeding, especially if taken with blood-thinning medications like warfarin. Consider reducing doses or alternating intake.

Consider the following tips:

• Check for interactions before taking multiple supplements.
• Space out conflicting supplements for better absorption.
• Consult a healthcare provider before taking multiple supplements or medications.
• Tell your healthcare provider about all the supplements or medications you're taking if you already are.

Source: EatingWell. Isabel Vasquez, RD, LDN. January, 2025.