Quick answer
NIH gives 11 mg of zinc a day in pregnancy for women 19 and older and an upper limit of 40 mg. A Cochrane review of 21 trials in over 17,000 women reported a small difference in preterm birth and none in other main outcomes. NIH says 50 mg or more for weeks can block copper absorption.1,2
Key facts
- NIH gives 11 mg of zinc a day in pregnancy for women 19 and older, and 12 mg for teens, 3 mg more than before pregnancy.1,3
- The upper limit is 40 mg a day for adults and 34 mg for teens 14 to 18, including in pregnancy, from all sources.1,3
- A Cochrane review of 21 trials reported a small difference in preterm birth and no clear difference in other main maternal or newborn outcomes.2
- Doses of 50 mg of zinc or more over weeks can inhibit copper absorption, reduce immune function and lower HDL cholesterol.1,3
- In 11% of US pregnant women, zinc intake from food and supplements was below the estimated average requirement.1
What NIH says about zinc in pregnancy
NIH says the amount of zinc needed rises during pregnancy to supply fetal growth. It recommends 3 mg a day more than for women who are not pregnant, and it lists women who are pregnant or lactating among the groups more likely to take in too little.1
The recommended amount is 11 mg a day during pregnancy and 12 mg while breastfeeding, or 12 mg and 13 mg for teens.1
In national data from 2001 to 2014, 11% of pregnant women took in less zinc from food and supplements than the estimated average requirement.1
The upper limit for adults is 40 mg of zinc a day from all sources: food, drinks, supplements and medicines, including during pregnancy and breastfeeding. It is 34 mg for teens aged 14 to 18 and lower for children. It is set to protect copper status and does not apply to people given zinc as medical treatment by a doctor.1,3
What did the Cochrane review of zinc in pregnancy find?
The review pooled 21 randomized trials with over 17,000 women and their babies. It reported a small difference in preterm birth, with a risk ratio of 0.86 (0.76 to 0.97) in 16 trials, mostly in women of low income, and no clear difference in low birth weight or for any of the other main maternal or newborn outcomes.2
The authors found no convincing evidence that zinc supplements in pregnancy bring other useful benefits, and they noted that the preterm result could reflect poor nutrition in the groups studied. NIH's fact sheet gives a similar summary: routine supplementation does not appear to change low birth weight, stillbirth or neonatal death, and may affect preterm birth.1,2
A harm signal is described in one trial in 400 pregnant women with HIV in Tanzania. Taking 25 mg a day of zinc until 6 weeks after delivery made no difference to birth weight, the length of pregnancy or fetal death, but the supplements blunted the rise in hemoglobin between baseline and 6 weeks postpartum.1
Can zinc supplements affect copper in pregnancy?
NIH's upper limit is set to protect copper. Doses of 50 mg a day or more over weeks can inhibit copper absorption, and NIH reports that a marker of copper status fell in people taking about 60 mg a day for up to 10 weeks. The sources checked do not describe this specifically in pregnant women.1,4
Taking 50 mg of zinc a day or more for weeks can block copper absorption and lower copper status, reduce immune function and lower HDL cholesterol.1,3
Food rarely supplies as much as 50 mg of zinc a day, so zinc from food alone is unlikely to cause too much.1
What about zinc oxide, pyrithione zinc and zinc PCA?
Zinc oxide, pyrithione zinc and zinc PCA are ingredients of skin and hair products rather than supplements. The sources on this page cover zinc taken by mouth. They do not report on these skin and hair products in pregnancy, which is not a finding either way. A pharmacist can read the label of a specific product.1
Who should ask a doctor about zinc in pregnancy
- Anyone pregnant who is considering more zinc than a prenatal vitamin holds, who should ask their doctor or pharmacist to check it against the 40 mg upper limit.1,3
- Anyone pregnant who takes a quinolone or tetracycline antibiotic, penicillamine or a thiazide diuretic.1
- Anyone pregnant with HIV, or with Crohn's disease, ulcerative colitis, celiac disease or a history of weight loss surgery, since zinc needs differ.1
- Anyone who uses zinc-containing denture cream every day.1
Questions people ask
Is zinc oxide safe during pregnancy?
The sources checked cover zinc taken by mouth, not zinc oxide in skin products, which is not a finding either way. Ask your doctor or pharmacist about a specific product.1
Is pyrithione zinc safe during pregnancy?
No source checked addressed pyrithione zinc shampoos in pregnancy. NIH's upper limit of 40 mg a day is for zinc from food, drinks and supplements. Ask your doctor or pharmacist.1
Is zinc PCA safe during pregnancy?
The sources checked do not address zinc PCA in skin products, which is not a finding either way. Ask your pharmacist.1
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Sources
- National Institutes of Health, Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals. Updated January 6, 2026. Opened 2026-10-07.
- Ota E, Mori R, Middleton P, Tobe-Gai R, Mahomed K, Miyazaki C, et al. Zinc supplementation for improving pregnancy and infant outcome. Cochrane Database Syst Rev. 2015;2015(2):CD000230. A Cochrane systematic review of randomized trials. Opened 2026-10-11.
- Office of Dietary Supplements, National Institutes of Health. Zinc: Fact Sheet for Consumers. Updated October 4, 2022. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Copper: Fact Sheet for Health Professionals. Updated October 18, 2022. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.