Short answer

We found no direct interaction between Ashwagandha and Calcium in the sources below, but they share a caution.

Both have a note about thyroid medicine or thyroid tests (see each one below).

Ashwagandha

What it is: A plant root used in traditional Ayurvedic and Unani medicine, often called an adaptogen.

What the research says: Several small trials of 6 to 8 weeks found people felt less stress and anxiety, with doses around 500 to 600 mg a day working better than lower ones. A few small studies suggest a modest sleep benefit. It has not been studied thoroughly.

Cautions

• Well tolerated for up to about 3 months; long-term safety isn't known.
• Mild side effects can include upset stomach, loose stools, nausea and drowsiness.
• It has been linked to liver injury in some people.
• Not for people who are pregnant or breastfeeding, or who have prostate cancer.

Medicines to check

• Thyroid medicine (ashwagandha may affect how the thyroid works)
• Diabetes and blood-pressure medicines
• Sedatives
• Medicines that suppress the immune system

In Holitro: Ashwagandha (500 mg per capsule)

Source: NIH Office of Dietary Supplements: Ashwagandha: Fact Sheet for Consumers (updated December 2023)

Calcium

What it is: The body's most abundant mineral; it builds bones and teeth and helps muscles, nerves and blood vessels work.

What the research says: Calcium supports bone health, especially when diet falls short. Vitamin D helps the body absorb it.

Cautions

• Upper limit from all sources: 2,500 mg a day for adults 19 to 50, and 2,000 mg from age 51.
• Some research links very high intakes to heart disease and prostate cancer risk.

Medicines to check

• Levothyroxine (thyroid medicine): keep doses apart
• Quinolone antibiotics: keep at least 2 hours apart
• Dolutegravir (HIV medicine) and lithium

In Holitro: Calcium Citrate (160 mg per capsule)

Source: NIH Office of Dietary Supplements: Calcium: Fact Sheet for Consumers (updated September 2023)

Check with your doctor or pharmacist, especially if you take medication.

Check your stack — free

Educational information only, not medical advice. This reflects general ingredient overlap, not a personalized safety review. Always check with your doctor or pharmacist before combining supplements, especially if you take medication, are pregnant or nursing, or manage a health condition. These statements have not been evaluated by the FDA.