Many foods that are not made from animal sources - vegan products - are still unhealthy, and the quality and composition of the food always remain crucial. It should also be noted that a shortage of certain nutrients can occur more quickly during pregnancy and breastfeeding period.
A well-composed vegetarian diet with some dairy and egg products (ovo-lacto-vegetarian) can meet the needs of the nutrients during pregnancy. For safety reasons, as is generally the case during pregnancy, supplementation and targeted counseling are recommended (interview with a trained professional or material from a specialized institution - such as nutrition companies).
In the case of a vegan diet (exclusive herbal products without appropriate additions of certain nutrients), the critical nutrients in the blood laboratory should be checked by a doctor and individual nutritional advice should be provided by an adequately trained specialist. A lack of certain nutrients can cause harm to the child (congenital defects) as well as complications during the pregnancy.
A deficiency can arise mainly for:
Zinc and proteins are more likely to be deficient when the vegetarian diet is relatively unbalanced (many white flour products and other sources of fast carbohydrates) and/or when certain foods are unbalanced combined.
As with iron, zinc is also reduced in absorption by the following factors: calcium compounds (e.g. in dairy products) and excessive copper doses (this means imbalances in copper and zinc intake), and ligands (binding substances) from foods of vegetable origin.
Therefore, with a high consumption of vegetable food, the zinc intake is recommended to increase about 30-50%.
Zinc is very important for many enzymes, for insulin storage, for the immune system and many other functions. The highest levels of zinc as for iron are in the liver, in meat (especially beef), fish and dairy products, but also legumes (lentils, beans) and whole grains (oats) have good quantities, although less is absorbed from the vegetable foods. With products from milk, legumes and whole grain, as mentioned, the absorption of some other substances can be reduced somewhat, but with balanced nutrition and exclusion of certain diseases, there is no deficit with vegetarian food (then you must not pay attention to extra Zinc-copper relation). In terms of deficits and diseases, nutrients should be analyzed in the blood. (Liver should not be consumed during pregnancy!)
Proteins are deficient on a vegan diet only when are consumed too little amounts of legumes, nuts, and seeds. The recommended doses of the bioactive forms of omega-3 fatty acids (DHA and EPA) are not met through the plant diet (except via vegan microalgae supplements). Omega-3 fatty acids DHA and EPA have shown beneficial effects on fetal and child brain development (EFSA: DHA and EPA support the brain, the eyes, and nerve development), and these fatty acids promote the health of pregnant and breastfeeding women. Relative deficiency does not immediately manifest itself in the form of deficiency symptoms at the level of defects or diseases.
Iron with vegetarian or purely vegan diet: Women need during the pregnancy the double dosage iron than before, but the higher iron intake in our cultures should preferably be from food, which provides better protection against overdose.
Iron in plants is less bioactive for humans (much less absorbable due to the binding form [2-5% on average] compared to iron from meat and fish [20-25% on average].) Therefore, vegans and vegetarians have some challenges -cover the need is more demanding.
To replenish the iron stores in the organism, one should separate the consumption of foods with good iron concentrations, 1-2 hours before and 3-4 hours later, from foods rich in calcium and oxalic acid. This should be followed at 4-5 meals a week (for lunch, for example, with a different combination than in the morning and evening).
Note: While some substances, such as calcium, oxalic acid, and certain phytochemicals reduce the absorption (absorption) of iron, by the simultaneous intake of vitamin C-rich foods, can be improved the absorption rate.
Vegetable foods with higher calcium content are soybeans (however, soy drinks have significantly less calcium than cow milk); sesame, nuts, dried figs, and cabbages also have higher calcium content. Because of the good iron content and otherwise many good effects by e.g. nuts and soya, especially the calcium from dairy products in a vegetarian diet is relevant.
Caution: calcium-rich may be the tap water in some regions.
Combine vegan foods of higher iron content (whole grain nuts and seeds) with Vitamin-C-rich foods. Good sources for Vitamin C are fruits such as currant, papaya, kiwi, etc.; vegetables or herbs such as fresh parsley, tomato concentrate, red paprika; fresh cress, etc.
An additional vitamin B12 supplementation is often necessary for a vegetarian diet, and it is necessary for vegan diets. A supplements dosage of 500μg Vitamin B12 per day is recommended.
It has been claimed by some that vegan diets are designed to meet certain algae and beer or food yeast to meet the vitamin B12 requirement. However, this does not necessarily guarantee adequate care.
Algae and yeast naturally do not contain bioavailable vitamin B12. Such could only be present if they are extra enriched with it (added supplementation). Certain yeast- or algae- products may contain vitamin B12, but most natural algae and yeast products do not contain it.
It may take years until clear symptoms due to vitamin B12 deficiency are seen, but this does not mean that no dysfunctions have been caused by it before. One should analyze it with attention.
For correct analysis of vitamin B12 deficiency or need, the bioactive form of vitamin B12 - e.g. the Holotranscobalamin (HoloTC) should be determined.
In addition to the measurement of HoloTC, the determination of homocysteine and methylmalonic acid (MMA) has proven to be diagnostically useful.
Vitamin B12 malabsorption may be due to the lack of intrinsic factor (IF), due to chronic atrophic gastritis (autoimmune gastritis). Helicobacter pylori infection can also cause the malabsorption of vitamin B12. Here are tests from the capillary blood or the H2-test from the breath air possible.
For pregnant and breastfeeding women with a vegan or vegetarian diet, vitamin B12 doses of 500μg to 1000μg daily are recommended, as far as it should be supplemented sufficient safety. Due to the low bioavailability, higher doses of supplementation are needed.
The vitamin B12 daily requirement in humans is assumed to be around 1.5 - 2 μg. The German Society for Nutrition (DGE) currently recommends 4.0μg of vitamin B12 per day for adolescents and adults and in pregnant women 4.5μg and 5.5μg for breastfeeding daily.
Breast-fed children get vitamin B12 by the milk as far as the mother is well supplied for; from the 4-12 month of life the daily requirement is declared to 1.4μg; from 1-4 years to 1.5μg, from 4.-7 years to 2.0μg, from 7.-10. years to 2.5μg, from 10.-13. years to 3.5μg and from the age of 13 years at 4.0μg per day.
The higher supplements dosage of 500μg Vitamin B12 per day is recommended because the recommended doses did not produce any undesirable effects, and because of the desire to be safe due to different absorption rates.
Absorption occurs through passive diffusion on the mucous membranes of the mouth and small intestine; and through the gastric intrinsic factor, which generates a transport protein and causes vitamin B12 uptake in the small intestine. For this intrinsic factor, uptake is estimated at an average of maximum of 1.5 - 2 μg per meal and there are genetic variances that lead to uptake (some lead to significant deficiency).
Even at normal conditions, the intake of vitamin B12 is therefore limited in a time window. Only a fraction (about 1-2%) of the dose is absorbed via passive diffusion.
The temporal distribution on Vitamin B12 intake 3 times a day has such advantages, as the intrinsic factor then better utilizes the transport capacity.
Adding significantly higher doses of vitamin B12 results in higher absorption at the end (1-2% of passive diffusion). It is then possible to increase the intake (via intrinsic factor + passive absorption) with the administration of 1000μg vitamin B12 at once. The approximately 2μg above the intrinsic factor plus 1% of 1000μg. This results in the absorption of approximately 12 μg of vitamin B12.
With 500μg supplementation, pregnant and breastfeeding women with a vegan diet can provide adequate recommendations according to the DGE recommendations, insofar as there are no intake disorders.
If absorption disorders occur at the same time, a higher dose may be necessary. This could be for example in some anemia patients. Therefore, laboratory control should always be aimed at people with a vegan diet, for more security.
With a vegetarian or vegan diet, pregnant and breastfeeding women should seek medical advice and nutrition consultation by a specialist (or use material from a specialized institution), and to be on the safe side, have some blood laboratory analysis done. The women should supplement vitamin B12 for about 500µg per day in any case.
Even with a balanced composition of the diet - whether omnivore, vegetarian or vegan - some supplements are recommended already during pregnancy planning as well as during pregnancy and lactation for safety reasons. First and foremost are folic acid and, if necessary, iodine, and after appropriate analyzes, other nutrients.
In vegan diet vitamin B12 is essential to supplement, in a vegetarian diet, there may be a need for it.
Prof. Dr. Werner Seebauer is Dean of Studies – Association of German Preventologists, Head of Preventive Medicine Department of Institute of Transcultural Health Sciences (European University Viadrina) and Head of Preventive Medicine – NESA (The New European Surgical Academy). Since 2000, prof. dr. Werner Seebauer worked only in preventive medicine, after ten years spent at the Frankfurt University Hospital. He is also involved in the medical professionals training for nutrition and prevention.
