If you eat a vegetarian diet during pregnancy or breastfeeding, take vitamin B12 daily; include animal foods in the baby’s complementary diet, and consult a doctor before making it vegan

A bottle of vitamin B12 supplements costs a few dozen yuan; take one tablet daily. Adding eggs, meat or fish to complementary foods does not cost much. The hard part is changing your mind when the whole family believes vegetarian eating is healthier.

The US Centers for Disease Control and Prevention reported two children in 2003. Both had been breastfed by vegetarian mothers, both were vitamin B12 deficient, and both had poor growth and developmental delay. The first child’s mother had followed a vegan diet for 7 years. The child was hospitalized at 15 months with severe anemia; brain MRI showed global cerebral atrophy. B12 treatment brought improvement, but at 32 months speech and language remained delayed. The report identifies maternal dietary deficiency as the most common cause of B12 deficiency in infants and young children. In breastfed infants, it generally appears at 4–8 months. Prolonged deficiency can leave irreversible neurological damage in some children, depending on how severe it was and how long it lasted. The only reliable unfortified sources are animal foods: meat, dairy and eggs. Most naturally occurring B12 in plants is not usable by the human body. B12-fortified cereals, soy drinks and nutritional yeast can provide reliable, regular sources. The report urges vegetarians, particularly pregnant and breastfeeding women, to understand the B12 content of their food or seek nutritional advice. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition’s 2017 position paper on complementary feeding states that all infants should receive iron-rich complementary foods, including meat or iron-fortified foods. Vegan diets should be used only with appropriate medical or dietetic supervision, and parents should understand the serious consequences of failing to follow supplementation advice. China’s National Health Commission’s 2020 core feeding guidance requires at least 4 kinds of complementary food daily, including at least one animal food, one vegetable and one grain or starchy root food.

Centers for Disease Control and Prevention (2003). Neurologic impairment in children associated with maternal dietary deficiency of cobalamin—Georgia, 2001. MMWR, 52(4), 61-64. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5204a1.htm；Fewtrell M, Bronsky J, Campoy C, et al. (2017). Complementary Feeding: A Position Paper by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) Committee on Nutrition. Journal of Pediatric Gastroenterology and Nutrition, 64(1), 119-132. https://doi.org/10.1097/MPG.0000000000001454；国家卫生健康委办公厅 (2020). 婴幼儿喂养健康教育核心信息. https://www.gov.cn/zhengce/zhengceku/2020-08/01/content_5531915.htm；Melina V, Craig W, Levin S (2016). Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. Journal of the Academy of Nutrition and Dietetics, 116(12), 1970-1980. https://doi.org/10.1016/j.jand.2016.09.025（备注里的反方）

Disputed: the Academy of Nutrition and Dietetics’ 2016 position is that appropriately planned vegetarian and vegan diets are suitable for all stages of life, including pregnancy, breastfeeding, infancy and childhood. It also specifies that vegans need a reliable B12 source, such as fortified foods or supplements. The disagreement concerns whether babies can be fed a vegan diet; there is no disagreement over the need for B12 supplementation. Lacto-ovo vegetarian diets carry less risk, but people who rarely eat eggs or dairy can still become deficient. The second child’s mother in the report had been vegetarian for 20 years and ate negligible amounts of meat, fish and dairy. Early B12 deficiency symptoms are nonspecific; the CDC says anemia markers are not appropriate screening tools. If a child grows slowly or falls behind developmentally, tell the doctor that the family eats a vegetarian diet; the doctor decides which tests are needed. Do not refuse prescribed treatment because you trust folk remedies; see Section 16, item 4 (do not stop standard treatment to try folk remedies). For introducing complementary foods, see item 4 of this section (start complementary foods at 6 months); for folic acid during pregnancy, see Section 27, item 1 (take 0.4 mg folic acid daily).