Vegan diet and nutritional deficiencies: appropriate foods and vitamin B12 supplements reduce health risks

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

The vegan diet, characterized by the total absence of animal products, can cause nutritional deficiencies that are detrimental 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, including the use of vitamin supplements, so as to be guaranteed the right intake of essential nutrients.

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

Vegan eating: the pros and cons of an increasingly popular diet

The vegan diet involves eating only plant foods, sometimes excluding products such as honey. This eating style, like vegetarian eating, is becoming increasingly popular among the Western population. According to reports from the German Society of Human Nutrition, vegans are mainly women, who are young, educated and affluent, live in cities and follow a healthy lifestyle. In Germany, vegans represent between 0.1 percent and 1 percent of the population, or 81,000 to 810,000 people, while, according to the British Vegan Society, veganism is also growing rapidly in Great Britain where it involves at least 542,000 people. In Italy, the latest statistics report that in 2016 the number of people following a vegan diet reaches 1 percent 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, in fact, the risk of diet-related diseases often stems from an imbalance between the consumption of plant and animal foods; in particular, the excessive use of red meat, sausages, and other foods containing animal fats, as well as the low consumption of whole grain products, vegetables, and fruits, can increase the risk of cardiovascular disease, obesity, and type 2 diabetes mellitus. 

Several studies have revealed that those who follow a vegetarian diet are at less risk of metabolic syndrome, cardiovascular disorders, ischemic heart disease, and some types of cancer. However, some research has confirmed that even omnivores who consume few foods of animal origin, preferring vegetables, grains and fruits, have the same mortality rate as vegetarians.

 These results indicate how a mixed diet, but one characterized by low consumption of meat and meat products and exact amounts of fish, can contribute to the maintenance of health status, averting the danger of nutritional deficiencies. In fact, it is well known that a diet completely devoid of foods of animal origin can cause deficiencies in some essential nutrients, such as omega-3 fatty acids, cholesterol, essential amino acids, minerals such as calcium, iron, and zinc, and vitamins such as vitamin D, riboflavin, and vitamin B12 (also called cobalamin).

The vegan diet is often associated with a vitamin B12 deficiency 

In light of these considerations, the recently published paper German Nutrition Society reports how diets that totally exclude certain foods cannot be recommended and recommended for pregnant or lactating women, children and adolescents, as the lack of the nutrients listed before can endanger health. In any case, those who choose to follow a vegan diet should use supplements to avoid specific nutritional deficiencies, especially with regard to vitamin B12. The latter represents one of the nutrients most prone to deficiency when not consuming animal products, being contained mainly in meat, fish and eggs.

 Vitamin B12 plays several key roles in the body, including regulating the concentration of homocysteine in the blood; low levels of B12 are associated with high concentrations of homocysteine, an 'important cardiovascular risk factor. This deficiency can also impair DNA synthesis in cells, cause a form of anemia called megaloblastic anemia, and result in neurological disorders. As reported by the publication's authors, 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, in vegans and vegetarians, the proper supply of nutrients essential to maintaining good health. 

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

Views at the international level

In addition to the German Nutrition Society, other international bodies have spoken out in regard to the vegan diet, often with conflicting opinions. In the past, the American Academy of Nutrition and Dietetics, the Australian National Health, and the Canadian Paediatric Society have affirmed that a properly planned vegan diet, which includes suitable foods and supplements as well as fortified ones, is, from a nutritional point of view, adequate during all stages of life including pregnancy and lactation. 

Of the same opinion is the British Nutrition Foundation, whose experts have confirmed that a proper vegetarian or vegan diet may be advisable, but not the more extreme diets, such as the macrobiotic or raw diet, which are often low in calories and provide a totally insufficient and inadequate range of micronutrients for children. Similarly, Portugal's National Program for the Promotion of a Healthy Diet recommends that vegan mothers who breastfeed their babies continue this period until they are two years old, during the weaning phase, to ensure that babies receive enough high-quality milk protein. 

According to Vegan Society spokesman Jimmy Pierson, with the right skills and knowledge it is possible to follow a healthy vegan diet without any health risks. Also supporting this idea is the British Dietetic Association, which has signed a memorandum of understanding with the Vegan Society to "Ensure that physicians and health professionals are aware that a well-planned vegan diet can ensure healthy living at every age and stage of life." Indeed, Pierson mentioned that there are other sources of vitamin B12, such as grains, yeast extracts, any other food fortified with vitamin B12, and supplements.

What does a proper vegan diet consist of?

Various nutritional recommendations related to vegan food and nutrition have been published by various scientific societies and experts in the field in recent years. Although with some differences, the basic points of vegan nutrition see vegetables, legumes, and fruits as the key foods for maintaining proper health due to their high micronutrient density, high dietary fiber content, presence of phytochemicals, and their potential for prevention of various nutrition-related diseases. 

Vegetarians and vegans are recommended foods such as green leafy vegetables and nuts, and whole grains and potatoes should also be an essential component of meals. Legumes, nuts, and oil seeds are the main sources of protein, B vitamins, zinc, and iron in this dietary regimen, as is the use of fortified products, for example, with calcium. As an alternative to the latter, the consumption of vitamin B12, vitamin D, and mineral supplements is recommended.

A diet that must be followed carefully

In conclusion, according to the German Nutrition Society adhering to a vegan diet can be risky especially during pregnancy and lactation or in the growth stages. However, it is a personal choice and can only be followed under conditions that manage to meet nutritional needs if the following guidelines are followed:

• Use a vitamin B12 supplement long-term and under regular medical supervision
• Very specifically select foods rich in particular nutrients and fortified foods
• Modify one's 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.