Vegan and Vegetarian Diets During Pregnancy and Lactation
by Anne Eglash MD, IBCLC, FABM
The maternal diet during pregnancy is one aspect of a fetus’s environment that can play a role in the child’s long term health. According to the Academy of Nutrition and Dietetics, inadequate levels of proteins, iron, folic acid, vitamin D, calcium, iodine, omega-3 fatty acids and vitamin B12 have been shown to predispose the child to chronic conditions later in life, such as obesity, diabetes, cardiovascular disease and neurodevelopmental delays.
Vegans and vegetarians are at risk for some of these deficiencies, depending on their diets. Vegans tend to be a relatively homogeneous group, not eating anything that is animal based. Vegetarians avoid meat, but are heterogeneous in their diets, depending on whether they eat fish, eggs, and/or dairy products. For the purpose of this week’s CQW, we will assume that vegetarians eat eggs and dairy (lacto-ovo-vegetarianism).
According to the well-referenced scientific article referred to for this week’s CQW, pregnant women don’t need to increase their calorie requirements in the first trimester. By second trimester they need approximately 260-350 extra calories per day, and in the third trimester 452-500 extra calories per day.
Pregnant women in general may need nutritional supplementation for iron, folic acid, vitamin D, choline, iodine, calcium, and essential fatty acids.
- Vegetarians and vegans need more grams of protein per day than meat eaters.
- Pregnant and lactating vegans are advised to ingest 1200mg-1500mg of calcium per day, which is 20% more than what is recommended for omnivores.
- Vegans ingest more vitamin D than omnivores because of their intake of broccoli, beans, and leafy greens.
- Kale, broccoli and bokchoi have more calcium bioavailability (easier to absorb calcium from) as compared to spinach.
- Most prenatal vitamins do not supply the 1000-2000 units of vitamin D needed per day during pregnancy and lactation.
- A multivitamin with 100% Recommended Daily Allowance for vitamin B12 is adequate for vegans.
- All vegans need iron supplementation during pregnancy.
- The best source of iodine is iodized salt.
See the Answer
Vegetarian and vegan diets have increased worldwide in the last decades, according to the knowledge that they might prevent coronary heart disease, cancer, and type 2 diabetes. Although plant-based diets are at risk of nutritional deficiencies such as proteins, iron, vitamin D, calcium, iodine, omega-3, and vitamin B12, the available evidence shows that well planned vegetarian and vegan diets may be considered safe during pregnancy and lactation, but they require a strong awareness for a balanced intake of key nutrients. A review of the scientific literature in this field was performed, focusing specifically on observational studies in humans, in order to investigate protective effects elicited by maternal diets enriched in plant-derived foods and possible unfavorable outcomes related to micronutrients deficiencies and their impact on fetal development. A design of pregestational nutrition intervention is required in order to avoid maternal undernutrition and consequent impaired fetal growth.
I have been a lacto-ovo-pesco-vegetarian for 45 years, and I learned stuff from this article!
Vegetarians and vegans need more protein because it is harder to absorb protein from plants than from meat. Calcium is also harder to absorb, partially because of fibers and other substances in a plant-based diet that bind calcium in the gut. For example, broccoli and bokchoi have fewer oxalates than spinach, and oxalates bind calcium in the gut, making the calcium in spinach harder to absorb.
Vegans have less vitamin D in their diets. Although sunlight is the best source of vitamin D, it is also found in fish and egg yolks. Therefore, vitamin D supplementation is more important for vegans and some vegetarians than for omnivores.
The amount of vitamin B12 in a prenatal vitamin is not sufficient for a vegan, but is sufficient for an omnivore who consumes some animal products. Vegans should take an extra vitamin B12 supplement such as 100-250mcg a day.
Vegans and vegetarians are able to consume enough iron through plant sources such as legumes, raisins, black strap molasses, and iron fortified cereals, particularly if consumed along with foods high in vitamin C. Cooking in cast iron skillets also increases the iron content of foods.
Essential fatty acids, usually consumed as fish oil or DHA (docosahexaenoic acid) is very important for fetal brain and retinal development. Vegans can obtain essential fatty acids through flax seed, soy beans, walnuts, hemp seeds, and soybeans, but it is difficult to generate DHA from these fatty acids. Therefore, it is ideal for vegans to take a micro-algae DHA supplement during pregnancy and lactation.