Treatment of Zinc Deficiency in Pregnancy
For acquired zinc deficiency during pregnancy, provide 0.5-1 mg/kg per day of elemental zinc orally for 3-4 months, preferably using organic compounds like zinc gluconate, zinc histidinate, or zinc orotate which are better tolerated than inorganic forms like zinc sulfate. 1
Dosing and Formulation
The ESPEN 2022 micronutrient guidelines provide clear dosing for acquired zinc deficiency 1:
- Dose: 0.5-1 mg/kg per day of elemental zinc (Zn2+)
- Duration: 3-4 months of treatment
- Preferred formulations: Organic compounds (zinc histidinate, zinc gluconate, zinc orotate) show comparatively better tolerability than inorganic forms (zinc sulfate, zinc chloride)
- Route: Oral administration is standard
For a 60 kg pregnant woman, this translates to approximately 30-60 mg of elemental zinc daily.
Monitoring Requirements
Before initiating treatment, confirm zinc deficiency through laboratory testing 1:
- Measure plasma zinc to confirm clinical deficiency
- Simultaneously measure CRP and albumin for proper interpretation, as inflammation and hypoalbuminemia can falsely lower zinc levels
- Repeat measurements as needed based on clinical response
Important Clinical Context
The evidence for zinc supplementation improving pregnancy outcomes is limited. A 2021 Cochrane review of over 18,000 women found that zinc supplementation may result in little or no difference in reducing preterm births, stillbirth, perinatal deaths, low birthweight, or small-for-gestational age babies 2. This suggests that while treating documented deficiency is appropriate per guidelines, routine supplementation in zinc-replete pregnant women is not beneficial.
However, one study in Bangladesh showed that maternal zinc supplementation (30 mg daily) reduced acute diarrhea, dysentery, and impetigo in low-birthweight infants, though this benefit was not seen in normal birthweight infants 3. This suggests potential benefits in populations with high rates of malnutrition and low birthweight.
Special Circumstances
If the pregnant patient has increased gastrointestinal losses (fistulae, stomas, diarrhea) and requires parenteral nutrition, IV zinc up to 12 mg per day should be provided for as long as losses persist 1.
Key Caveats
- Zinc supplementation in well-nourished populations (like Denmark) showed no benefits 4, emphasizing the importance of documenting actual deficiency before treatment
- The prevalence of zinc deficiency increases during pregnancy even with supplementation 5, suggesting that addressing underlying nutritional and non-nutritional causes may be necessary
- Avoid zinc toxicity: symptoms appear when ingestion exceeds 1-2 g of zinc 1