News to me. Has this woman had a second opinion?.Could she be reacting to another substance in foods/supplents? Vitamin C is an essential nutrient. Without vitamin C intake the "natural level" would be a deficiency. (Scurvy) Although milk levels of C are higher than plasma levals (Nutrition During Lactation, IOM). If the plasma levels are very low, the breastmilk would be low too. This could be addressed in the infant with a C supplement (NOT over RDA, and best to involve the infant's pediatrician) -- although would likely contribute to mother becoming deficient more quickly. (RDA, 10th edition reports one study that showed deficiency symptoms developing in as short a time as 24 days. The study subject weren't lactating. RDA is set at 60 mg/day for women, and 95 mg/day for lactating women--first 6 mo.) I would also be very concerned about mother's intake of other nutrients.