Is Vitamin C safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Vitamin C. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
Sixty healthy lactating women between 1 and 6 months postpartum exclusively breastfeeding their infants were given vitamin C 500 mg plus vitamin E 100 IU once daily for 30 days, or no supplementation. Infants of supplemented mothers had increased biochemical markers of antioxidant activity in their urine. Clinical outcomes were not reported.[ 24 ] Eighteen preterm infants, seven of whom were less than 32 weeks gestational age, who were fed pooled, Holder-pasteurized donor milk beginning during the first three days of life had their average blood plasma ascorbic acid concentrations decrease from 15.5 mg/L at birth to 5.4 mg/L by 1 week of age, and to 4.1 mg/L by 3 weeks of age. The authors described the 1- and 3-week levels as subtherapeutic ( 6 mg/L) and indicative of inadequate intake, potentially jeopardizing postnatal growth potential.[ 25 ] Although this study was conducted before advances in the provision of parenteral nutrition and enteral milk fortification for preterm infants, contemporary studies suggest that inadequate vitamin C intake from pooled, pasteurized donor milk may be a potential health problem for preterm infants receiving donor milk.[ 17 ]
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels Average mature milk vitamin C concentrations are 50 to 90 mg/L in mothers consuming adequate vitamin C in their diet.[ 4 - 8 ] Milk concentrations are not markedly increased with routine daily multivitamin supplementation.[ 6 , 8 - 10 ] Vitamin C levels are higher in colostrum by 10 to 20 mg/L compared with mature milk.[ 11 , 12 ] Levels are relatively stable until after 12 months postpartum when they begin to decrease slightly and reach 30% of previous levels by 18 to 24 months postpartum.[ 4 ] Milk levels correlate with blood levels, and both are influenced by maternal diet, particularly in poorly nourished mothers whose milk levels respond more robustly to increases in dietary vitamin C intake.[ 13 , 14 ] Mothers who smoke have lower milk vitamin C levels than those who do not, which is consistent with the known negative effect of smoking on human blood vitamin C levels.[ 15 , 16 ] Milk from poorly nourished mothers with inadequate vitamin C intake has vitamin C levels of 30 to 50 mg/L during the first postpartum week, and 20 to 30 mg/L in mature milk.[ 15 - 17 ] Supplementation of deficient mothers with doses of 100 to 200 mg daily increases the mature milk level slightly to 40 to 60 mg/L.[ 18 , 19 ] Among mothers living in rural The Gambia, West Africa, blood and milk vitamin C levels increased during seasonal periods of increased dietary intake from vitamin C-rich fruit. Milk levels were 50 to 60 mg/L during April to June when mango availability and consumption was highest, and 40 to 50 mg/L during December to February when orange availability and consumption was highest. Milk levels were 20 to 30 mg/L at other times of the year when consumption of these fruits was lowest. Mothers were concurrently taking a dietary supplement providing 35 mg daily of vitamin C throughout the year.[ 13 ] Pooled and pasteurized donor milk from milk banks in Ontario and British Colombia, Canada had average vitamin C levels of only 17.7 mg/L (range 1.9 to 43.2 mg/L
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.