Zinc (Serum)
Zinc is an essential trace element involved in immune function, DNA synthesis, and fetal growth. Maternal zinc concentrations decline gradually across pregnancy due to hemodilution and active placental transport.
| Units | Nonpregnant Adult | 1st Trimester | 2nd Trimester | 3rd Trimester |
|---|---|---|---|---|
| µg/dL | 75 – 120 | 57 – 88 | 51 – 80 | 50 – 77 |
| µmol/L | 11.5 – 18.5 | 8.7 – 13.5 | 7.8 – 12.2 | 7.7 – 11.8 |
Causes of low zinc (hypozincemia)
- Physiologic decline during pregnancy
- Low dietary intake (vegetarian, vegan diets without supplementation)
- Malabsorption (celiac disease, Crohn’s, short bowel)
- Chronic diarrhea
- Liver disease (low albumin → reduced zinc binding)
- Alcohol use disorder
- Nephrotic syndrome (urinary loss)
- Bariatric surgery
- Acrodermatitis enteropathica (rare genetic disorder)
- High phytate intake (binds intestinal zinc)
Causes of high zinc (hyperzincemia)
- Excess supplementation
- Denture adhesive creams containing zinc
- Multivitamin excess
- Hemolysis during blood draw (pseudoelevation)
- Acute infection or inflammation
- Heavy metal contamination / assay interference
- Renal insufficiency
- High-dose copper deficiency treatment
References
- Abbassi-Ghanavati M, Greer LG, Cunningham FG. Pregnancy and laboratory studies: a reference table for clinicians. Obstet Gynecol. 2009;114:1326–31. PMID: 19935037.