What is the role of vitamin C in pregnancy?

Role of Vitamin C in Pregnancy

Pregnant women require increased vitamin C intake (an additional 10-20 mg/day above non-pregnant recommendations) to support fetal development, maintain maternal health, and potentially reduce pregnancy complications. 1

Functions of Vitamin C During Pregnancy

Vitamin C serves several critical functions during pregnancy:

• Fetal development support: Actively transfers from mother to developing fetus 1
• Collagen synthesis: Essential for proper formation of connective tissues, blood vessels, and skin
• Antioxidant protection: Provides defense against oxidative stress for both mother and fetus
• Epigenetic regulation: Recently discovered role in DNA and histone hydroxylation affecting fetal development 1
• Iron absorption enhancement: Improves absorption of non-heme iron, helping prevent anemia
• Immune system support: Maintains maternal immune function during pregnancy

Vitamin C Requirements in Pregnancy

Pregnancy increases vitamin C requirements due to:

• Hemodilution (blood volume expansion) during pregnancy 1
• Active transfer of vitamin C to the fetus 1
• Enhanced metabolic demands of pregnancy

Most health authorities recommend:

• Additional 10-20 mg/day for pregnant women above non-pregnant recommendations 1
• Total daily intake of 85-120 mg/day depending on country guidelines 1, 2

Clinical Significance and Outcomes

Maternal Benefits

• Reduced risk of pregnancy complications: Women with adequate vitamin C status have fewer pregnancy complications compared to those with low levels 3
• Decreased risk of premature rupture of membranes: Vitamin C supplementation may reduce risk of PPROM in women with history of this complication 4
• Reduced risk of placental abruption: High-quality evidence shows decreased risk with adequate vitamin C intake 5

Fetal Benefits

• Improved fetal growth: Maternal vitamin C intake is positively associated with fetal biparietal diameter and abdominal circumference 6
• Better infant growth: Higher maternal vitamin C consumption correlates with improved weight gain from birth to 6 months 6
• Umbilical cord blood levels: Maternal vitamin C status directly influences newborn vitamin C levels 3

Risk of Deficiency

Women at higher risk of vitamin C deficiency during pregnancy include:

• Those with type 1 diabetes (increased risk of complications with poor vitamin C status) 1, 3
• Women with history of pregnancy complications 1
• Those with poor dietary intake of fruits and vegetables
• Women who have undergone bariatric surgery 1

Supplementation Recommendations

For most pregnant women:

• 85-120 mg/day total vitamin C intake 1, 2
• Food sources should be primary (fruits and vegetables) 6

For high-risk women (post-bariatric surgery):

• Higher supplementation may be required (≥90-120 μg/day) 1
• Monitor serum levels at least once per trimester 1

Clinical Pearls and Pitfalls

• Hypovitaminosis C risk: Women with vitamin C levels <23 μmol/L have 2.4-fold higher risk of pregnancy complications 3
• Monitoring: For high-risk women, check vitamin C status each trimester 1
• Balance is key: While deficiency increases risks, very high-dose supplementation (>1000 mg/day) has not shown additional benefits and may have adverse effects 2, 5
• Diabetic pregnancies: Special attention should be paid to vitamin C status in women with diabetes, as poor vitamin C status correlates with increased complications 1, 3

Vitamin C's multifaceted role in pregnancy highlights its importance as an essential nutrient for maternal health and optimal fetal development. Ensuring adequate intake through diet and appropriate supplementation when needed can contribute to better pregnancy outcomes.