Vegan Diet and Nutritional Deficiencies: Appropriate Foods and Vitamin B12 Supplements Reduce Health Risks

Vegan diet and nutritional deficiencies: vitamin B12 and appropriate foods improve health

The vegan diet, characterized by the complete absence of animal products, can cause nutritional deficiencies harmful to health, such as those of certain amino acids, polyunsaturated fatty acids, and especially vitamin B12. For vegans, therefore, it is very important to follow a planned and well-balanced diet, which also includes the use of vitamin supplements, in order to guarantee the right intake of essential nutrients.

This is reported by an article published by the German Nutrition Society in the scientific journal Ernaehrungs Umschau International.

Vegan nutrition: the pros and cons of a growing diet

The vegan diet involves consuming exclusively plant-based foods, sometimes excluding products such as honey. This dietary style, like vegetarianism, is becoming increasingly popular among the Western population. According to the German Nutrition Society, vegans are mainly women, young, educated, and affluent, living in cities and following a healthy lifestyle. In Germany, vegans represent between 0.1% and 1% of the population, equal to 81,000 - 810,000 people, while, according to the English Vegan Society, veganism is rapidly growing in Great Britain, involving at least 542,000 people. In Italy, the latest statistics show that in 2016 the number of people following a vegan diet reached 1% of the population. The main reasons for choosing a diet free of animal products are mainly ethical, but also ecological and health-related. According to current knowledge, the risk of diet-related diseases often derives from an imbalance between the consumption of plant and animal foods; in particular, excessive use of red meat, processed meats, and other foods containing animal fats, as well as low consumption of whole grain products, vegetables, and fruit, can increase the risk of cardiovascular diseases, obesity, and type 2 diabetes.

Several studies have revealed that those following a vegetarian diet are less exposed to the risk of metabolic syndrome, cardiovascular disorders, ischemic heart disease, and certain types of cancer. However, some research has confirmed that even omnivores who consume few animal-based foods, preferring vegetables, cereals, and fruit, have the same mortality rate as vegetarians.

These results indicate that a mixed diet, but characterized by low consumption of meat and derivatives and precise amounts of fish, can contribute to maintaining health, avoiding the risk of nutritional deficiencies. It is known, in fact, that a diet completely free of animal foods can cause deficiencies of some essential nutrients, such as omega-3 fatty acids, cholesterol, essential amino acids, minerals such as calcium, iron, zinc, and vitamins like vitamin D, riboflavin, and vitamin B12 (also called cobalamin).

Vitamin B12 deficiency is often associated with a vegan diet

In light of these considerations, the recent document published by the German Nutrition Society reports that diets that completely exclude certain foods cannot be recommended to pregnant or breastfeeding women, children, and adolescents, as the lack of the nutrients listed above can endanger health. In any case, those who choose to follow a vegan diet should use supplements to avoid specific nutritional deficiencies, especially concerning vitamin B12. The latter represents one of the nutrients most at risk of deficiency when animal products are not consumed, being mainly contained in meat, fish, and eggs.

Vitamin B12 plays several fundamental roles in the body, including regulating homocysteine concentration in the blood; low B12 levels are associated with high homocysteine concentrations, an important cardiovascular risk factor. This deficiency can also impair DNA synthesis in cells, cause a form of anemia called megaloblastic anemia, and lead to neurological disorders. As reported by the authors of the publication, scientific evidence has shown that the use of vitamin B12 supplements, under medical advice, along with a diet rich in specific foods and fortified foods, can ensure, for vegans and vegetarians, the proper supply of essential nutrients to maintain good health.

In any case, as also cited by the German government website, any diet that does not include adequate levels of nutrients and energy cannot be recommended, and a diet that includes all food groups, including animal products, should be preferred.

International opinions

In addition to the German Nutrition Society, other international organizations have expressed opinions regarding the vegan diet, often with contrasting views. In the past, the American Academy of Nutrition and Dietetics, the Australian National Health, and the Canadian Paediatric Society stated that a properly planned vegan diet, which includes suitable foods and supplements, as well as fortified ones, is nutritionally adequate during all life stages, including pregnancy and breastfeeding.

The same opinion is held by the British Nutrition Foundation, whose experts have confirmed that a proper vegetarian or vegan diet can be recommended, but not more extreme diets, such as the macrobiotic or raw food diets, which are often low in calories and provide an entirely insufficient range of micronutrients for children. Similarly, the Portuguese National Program for the Promotion of a Healthy Diet recommends that vegan mothers breastfeeding their babies continue this period up to two years, during weaning, to ensure that children receive enough high-quality milk proteins.

According to the Vegan Society spokesperson, Jimmy Pierson, with the right skills and knowledge it is possible to follow a healthy vegan diet without any health risks. Supporting this idea is also the British Dietetic Association, which signed a memorandum of understanding with the Vegan Society to "ensure that doctors and health professionals are aware that a well-planned vegan diet can provide a healthy life at every age and stage of life." Pierson also reminded that there are other sources of vitamin B12, such as cereals, yeast extracts, any other foods fortified with vitamin B12, and supplements.

What constitutes a proper vegan diet?

Various nutritional recommendations related to vegan nutrition have been published by various scientific societies and experts in recent years. Although with some differences, the fundamental points of the vegan diet see vegetables, legumes, and fruit as the fundamental foods to maintain good health due to their high micronutrient density, high dietary fiber content, presence of phytochemicals, and their potential to prevent various nutrition-related diseases.

Vegetarians and vegans are recommended foods such as leafy green vegetables and dried fruit; moreover, whole grains and potatoes should be an essential component of meals. Legumes, nuts, and oilseeds represent the main sources of proteins, B vitamins, zinc, and iron in this diet, as well as the use of fortified products, for example with calcium. Alternatively, the consumption of vitamin B12, vitamin D, and mineral supplements is advised.

A diet to be followed carefully

In conclusion, according to the German Nutrition Society, following a vegan diet can be risky especially during pregnancy and breastfeeding or growth phases. It is, however, a personal choice and can be followed in conditions that meet nutritional needs only if the following guidelines are observed:

• use a vitamin B12 supplement long term and under regular medical supervision
• select very specifically foods rich in particular nutrients and fortified foods
• modify your diet in case of a specific nutritional deficiency
• consult nutrition specialists for information and advice.

Source: Vegan Diet Position of the German Nutrition Society (DGE) Margrit Richter, Heiner Boeing, Dorle Grünewald-Funk, Helmut Heseker, Anja Kroke, Eva Leschik-Bonnet, Helmut Oberritter, Daniela Strohm, Bernhard Watzl for the German Nutrition Society (DGE), Ernaehrungs Umschau international, 4/2016 9.