Vitamin C levels fluctuate in pregnancy due to hemodilution, altered transport, and increased fetal/placental utilization. The following reference intervals reflect trimester-specific physiologic changes.
| Units | Nonpregnant Adult | 1st Trimester | 2nd Trimester | 3rd Trimester |
|---|---|---|---|---|
| mg/dL | 0.4-1.0 | 1.0-1.4 | 0.8-1.2 | 0.8-1.2 |
| µmol/L | 23-57 | 57-80 | 45-68 | 45-68 |
Causes of Low Vitamin C Levels
- Poor dietary intake (low fruits and vegetables)
- Smoking (increases oxidative turnover of Vitamin C)
- Malabsorption (e.g., inflammatory bowel disease, gastric surgery)
- Hyperemesis gravidarum
- Acute or chronic illness increasing metabolic demand
- Increased fetal and placental utilization
- Hemodilution from expanded plasma volume
Clinical Notes
- Vitamin C is important for collagen synthesis, wound healing, and immune function.
- Low levels may increase risk of anemia, premature rupture of membranes, or impaired wound healing.
- Deficiency can coexist with poor intake of other micronutrients (folate, B vitamins).