Quick answer

Ask your pharmacist or doctor before combining. Calcium supplements taken at the same time as dolutegravir can lower the medicine's blood levels considerably, according to NIH and its label. The label gives separate instructions for taking them with food and without food, so the right schedule depends on your routine and your pharmacist should set it.^1,2

Key facts

NIH says calcium supplements taken at the same time as dolutegravir can reduce blood levels of the medicine substantially, apparently through chelation, a kind of binding.¹
The dolutegravir label lists oral calcium or iron supplements, including multivitamins that contain them, among products that lower dolutegravir levels.²
In the label's study, calcium carbonate taken with dolutegravir on an empty stomach lowered dolutegravir exposure by about 39%, while taken with a meal it made no clear difference.²
NIH's consumer and professional sheets describe a spacing rule but do not mention the label's separate instruction for taking the two with food.^1,3
MedlinePlus says dolutegravir is used with other medicines to lower the amount of HIV in the blood.⁴

Ask your pharmacist how far apart to take them

Calcium supplements taken at the same time as dolutegravir can lower its blood levels considerably. Its label explains when the two may be taken together with food and when they must be kept apart.^1,2,3

On the medicine's label

What does the dolutegravir label say about calcium?

MedlinePlus describes dolutegravir as an HIV integrase inhibitor that is used with other medicines to lower the amount of HIV in the blood. Its label includes a drug interaction table, and oral calcium or iron supplements, including multivitamins containing calcium or iron, are listed there as lowering dolutegravir levels.^2,4

The label then gives two instructions: one for when the medicine is taken with food and one for when it is taken without food. The second involves keeping the two products apart by a number of hours. This page does not repeat that gap, because it depends on how you take the medicine and your pharmacist should confirm it for your regimen.²

How much does calcium carbonate change dolutegravir levels?

The label reports a single-dose study in which participants took 50 mg of dolutegravir with 1,200 mg of calcium carbonate. Taken together on an empty stomach (12 participants), dolutegravir exposure, measured as the area under the curve, fell to about 61% of its usual level, roughly 39% lower. Taken together with a meal (11 participants), exposure was about the same as without calcium.²

A single dose in study participants shows how large the effect can be, not how it plays out over months of daily treatment. NIH says calcium carbonate is absorbed best with food and is also the calcium in some over-the-counter antacids, so the form is common.³

Why do NIH and the label read differently?

NIH's consumer sheet and its health professional sheet both say that calcium supplements taken with dolutegravir can lower its blood levels, and both give a spacing rule, which the professional sheet says comes from the labels approved by FDA. Neither mentions the separate instruction for taking the two with food, which the label does. Where sources differ in detail, the label is the more specific one, and your pharmacist can tell you which instruction fits how you actually take your medicine.^1,2,3

Which calcium products and which dolutegravir tablets does this cover?

The label's wording covers calcium supplements and multivitamins that contain calcium, so check the Supplement Facts panel of everything you take. The sources do not discuss calcium from food and drink such as milk, which is not a supplement. That is not a finding either way, so ask your pharmacist.²

If your HIV medicine is a single tablet that combines dolutegravir with other medicines, ask your pharmacist whether the same advice applies to it. Iron is treated the same way as calcium in the label's table, so the question also covers an iron supplement.²

What to ask your pharmacist about calcium and dolutegravir

Do I take dolutegravir with a meal every time, sometimes or never?
Which of my products contain calcium: a supplement, an antacid or a multivitamin?
Do I also take iron, which the label groups with calcium?
What changes if my meal times change?

Questions people ask

Can you take calcium with dolutegravir?

NIH and the label say calcium supplements can lower dolutegravir levels, and the label gives separate instructions for taking them with food and without food. Ask your pharmacist which applies to how you take your medicine.^1,2

Can you take calcium carbonate with dolutegravir?

Calcium carbonate is the form the label tested. On an empty stomach it lowered dolutegravir exposure by about 39%, and with a meal there was no clear difference. Ask your pharmacist how that applies to an antacid or supplement you use.²

Does calcium lower dolutegravir levels?

Yes, according to NIH and the label: taken at the same time, calcium supplements can reduce blood levels of the medicine substantially. The label's study found the size of the effect depended on whether the two were taken with food.^1,2

Does the calcium in a multivitamin count?

The label names multivitamins that contain calcium or iron along with calcium and iron supplements. Check the Supplement Facts panel and show it to your pharmacist.²

See what we make

Every product shows its whole label and what its lab report covers. The store opens soon.

See the Full Measure line

Sources

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.