Vitamin C is a water soluble vitamin found in fruit and vegetables. Also known as ascorbic acid, vitamin C is an important antioxidant (has a protective function in the body). Vitamin C protects cells and keeps them healthy, helps wound healing and aids the absorption of iron. It is popularly used for preventing and treating infections, fatigue and cancer.1 Our bodies can’t make vitamin C so we rely on food sources. Good sources of vitamin C include berries, peppers, kiwi, citrus fruits, leafy vegetables, tomatoes and more. Our kidneys carefully control the amount of vitamin C in the body keeping it at the right level and excreting any excess that isn’t needed. A deficiency in vitamin C causes scurvy (NHS link).
Vitamin C in breast milk
A well nourished mother with a healthy diet will have just the right concentration of vitamin C in her breast milk for her baby.
How will vitamin C in my diet affect breast milk?
Authors Lawrence and Lawrence 2 state that within 30 minutes of a mother being given vitamin C, increased vitamin C is measured in breast milk (p.131) and that levels in milk can be increased through diet (p.535).
How will vitamin C supplements affect breast milk?
Hoppu et al 3 found that taking vitamin C supplements didn’t appear to influence the concentration of vitamin C in a well nourished mother’s breast milk very much compared to taking vitamin C from the diet. Another study in 1985, also found that taking vitamin C supplements above a certain level (1000 mg/day) didn’t influence the concentration of vitamin C in a well nourished mother’s breast milk very much.4
In contrast, one study found that if poorly nourished mothers with very low levels of vitamin C in their bodies take vitamin C supplements, levels of vitamin C can be doubled or tripled in their breast milk.5
These studies suggest vitamin C is regulated in breast milk. Even with high oral doses there is only a moderate rise in concentration in breast milk (Hale, 2022).
Vitamin C lowering medications
Some medications can lower levels of vitamin C (and other vitamins and minerals) when taken regularly/long term and a nursing mother may need a careful assessment of her nutrient levels. A selection of medications that can deplete vitamin C are listed in Breastfeeding and Human Lactation 6e (2021 p478) and include several anti-inflammatory medications (eg. hydrocortisone, prednisone, aspirin), birth control medications and diuretics (eg bumetanide, furosemide).6
Can I take vitamin C while breastfeeding?
Yes, the National Institutes of Health Office of Dietary Supplements say the recommended daily allowance (RDA) for vitamin C in a breastfeeding mother over age 19 is 120 mg/day with a tolerable upper intake level of 2000 mg [accessed 25 July 2023].
Thomas Hale MD author of Hale’s Medications and Mothers’ Milk 2022 says only undernourished mothers need vitamin C supplementation. He warns that pregnant women should avoid excessive vitamin C as it could affect metabolism of the vitamin in the mother or baby’s liver, potentially causing “rebound scurvy” (lack of vitamin C) in the newborn baby.
What about high doses intravenously?
The kidneys control levels of vitamin C in the blood and levels of vitamin C are regulated in breast milk. However, in complementary medicine, when vitamin C is given in high concentrations intravenously (directly through a vein), vitamin C can reach 30-70 times higher levels in the blood compared to taking the equivalent amount orally (Hale, 2022). Thomas Hale speculates that vitamin C levels in breast milk would probably also be high, and might predispose babies to a higher risk of kidney stones. However use of intravenous (IV) vitamin C has not been studied in breastfeeding women (Hale, 2022). Hale makes the following observations:
- Mothers with poor kidney function, history of kidney stones, G6PD deficiency or the blood disease: paroxysmal nocturnal hematuria should avoid having IV vitamin C.
- Mothers of babies with poor kidney function and G6PD deficiency should avoid taking excessive doses of vitamin C.
- Breastfeeding mothers should avoid IV vitamin C or, if used, avoid breastfeeding for 12-24 hours after therapy.
If you do want to take higher than recommended doses of supplemental vitamin C, discuss this with a knowledgable health professional who will be able to advise you based on the amount of vitamin C already in your diet, any medical conditions you have and any medications or supplements you already take.
Safety of vitamin C
According to the Institute of Medicine, vitamin C has low toxicity with adverse effects mostly reported with doses above 3 g/day:
There is no evidence suggesting that vitamin C is carcinogenic or teratogenic or that it causes adverse reproductive effects. Reviews of high vitamin C intakes have indicated low toxicity (Johnston, 1999); adverse effects have been reported primarily after very large doses (greater than 3 g/day).
Smoking and vitamin C
Smoking while breastfeeding reduces the amount of vitamin C in a mother’s breast milk. Smoking causes a baby extra oxidative stress (a type of cell breakdown) so anything that reduces antioxidants e.g. beta carotene, vitamins C and E can cause more peroxidation (an undesirable reaction stimulated in the body by some toxins and infections) 7. The fact sheet by the Office of Dietary Supplements 2019 explains that a smoker needs additional vitamin C:
individuals who smoke require 35 mg/day more vitamin C than nonsmokers.
Vitamin C and mastitis?
Wambach and Riordan, 2015 8discuss that in the dairy industry, giving antioxidants such as vitamin E to cows helps to prevent mastitis. Vitamin C is one of the best known antioxidants and the authors mention that mothers with mastitis have reported taking vitamin C supplements to fight infection however they do not give any discussion on suitable amounts or success rates. Sheila Humphrey in The Nursing Mother’s Herbal also says:
Immune-System-stimulating herbs such as echinacea, adaptogenic or tonic herbs such as ginseng, and vitamin C are often recommended for treating mastitis.
Laboratory studies suggest how vitamin C may work against mastitis as it has been shown to limit Staphylococcus aureus.9
Vitamin C and milk supply
In Mother Food, p 123 author Hilary Jacobson lists vitamin C supplements as a possible anti-lactogenic food i.e. one that could decrease a milk supply. For some sensitive mothers, she says citrus fruits can be problematic and are also reputed to be anti-lactogenic.
Vitamin C and preventing allergy
Hoppu et al 10 noted a reduced tendency to atopy (tendency to develop allergies such as asthma or eczema) in the breastfed offspring of mothers with a diet rich in vitamin C. Interestingly the babies at risk of low vitamin C levels belonged to mothers with food hypersensitivity.
Summary
Vitamin C is an important vitamin for the body, levels are controlled by the kidneys. A breastfeeding mother with a healthy diet will have just the right amount of vitamin C in her breast milk. Dietary vitamin C has a greater influence on the levels in breast milk than taking supplements. Therapeutic doses (very high doses) of vitamin C are sometimes taken for certain health issues. When high levels of vitamin C are taken intravenously (directly in a vein) the levels in the blood are much higher than normal. The use of intravenous vitamin C has not been studied in breastfeeding women. Breastfeeding in medications author Thomas Hale recommends that breastfeeding women avoid excessively high doses both orally or intravenously.