Are Dietary Supplements Necessary in a Vegan Diet?

A vegetarian diet is a nutritional system that completely excludes the consumption of meat and products containing its components. However, it allows for the consumption of cereal products, dried seeds of legumes, nuts, mushrooms, fruits, vegetables, eggs, milk, and dairy products. There are, however, certain products for which classification as vegetarian is not straightforward. An example is honey, which is considered by some to be a product of animal origin, while others include it in their diet, often citing its health properties.

– Semi-vegetarianism – excludes the consumption of red meat and meat products, but allows the consumption of white meat, fish, seafood, milk and dairy products, fruit, vegetables, dried seeds of legumes, and nuts. – Pesco-vegetarianism – is a variation of semi-vegetarianism that excludes the consumption of white meat. – Lacto-vegetarianism – excludes the consumption of red meat, poultry, meat and meat products, fish and seafood, gelatin and rennet, but allows the consumption of eggs, milk and dairy products, fruit, vegetables, dried seeds of legumes, and nuts. – Lacto-ovo-vegetarianism – is similar to lacto-vegetarianism, but also allows the consumption of eggs. – Ovo-vegetarianism – excludes the consumption of milk and dairy products, but allows the consumption of eggs. – Veganism – excludes the consumption of all animal products, including meat, fish, seafood, eggs, and milk. – Raw veganism – excludes the consumption of all animal products and processed plant products, but allows the consumption of raw plant products. – Fruitarianism – excludes the consumption of all animal products and plant products, with the exception of fruit. – Macrobiotic diet – is based on the consumption of unprocessed grains such as wheat, oats, barley, spelt, corn, millet, or rice, as well as vegetables.

To benefit from a plant-based diet, it must be correctly composed and implemented, ideally under the guidance of an expert. The advantages of a plant-based diet include: - low saturated fat and high in essential unsaturated fatty acids, which have a beneficial effect on the lipid profile and prevent the development of cardiovascular disease; - high intake of vitamin C, which is characterized by strong antioxidant activity; - high potassium intake and low sodium intake, which has a positive impact on the water-electrolyte balance and the functioning of muscles, including the heart, and regulates blood pressure; - relatively low energy density and high nutritional value, which helps prevent overweight and obesity; - high intake of dietary fiber and low content of simple carbohydrates, which reduces the risk of type 2 diabetes, constipation, and colon cancer.

An improperly balanced vegetarian diet can have negative consequences for the body. The disadvantages of such a dietary regimen are: low energy supply, inadequate protein, calcium, vitamin B12, and vitamin D intake, low biological protein value - in vegetarian diets, individual sources often do not provide sufficient amounts of essential amino acids, hence plant-based foods should be appropriately combined to ensure that protein becomes a nutritional value for the body, excessive consumption of antinutrients (e.g. Phytates, Oxalates), which limit the absorption of minerals, and low digestibility of certain food components, e.g. animal protein is more digestible than plant protein. These factors can lead to osteoporosis, anemia, or protein deficiency. Therefore, it is important to educate about the importance of balancing vegetarian diets, which are not harmful to health in themselves. Only errors in nutrition, lack of specialized knowledge, and low awareness can increase the risk of diseases. It is also worth mentioning that being on a vegetarian or vegan diet does not automatically lead to a slim figure and good health - one can be vegetarian or vegan and still eat only french fries and chocolate every day. Like any dietary regimen, vegetarian diets also require proper balance and variety.

Certain variations of vegetarian diets do not necessitate any supplemental nutrients, provided that the meals are properly assembled. What does this entail in practice? Half of the plate should be filled with vegetables and fruits (with a focus on vegetables), which are a source of fiber, numerous vitamins, and minerals. Diversity in diet is crucial – the more diverse, the better. Whole grain products should take up approximately a quarter of the plate, including bread, pasta, rice, flakes, and primarily different types of grains. Grains constitute one of the most valuable sources of nutrients, frequently overlooked in diets, and devoid of artificial additives. The remaining portion of the plate should comprise plant-based protein sources, such as dry legumes, e.g., beans, peas, lentils, chickpeas, and chickpeas. Lacto-ovo-vegetarians may also include eggs or milk and dairy products in their diet, which provide an additional source of calcium. Protein and calcium can also be found in nuts and seeds (e.g., sesame, hemp, chia, sunflower seeds).

It is important to remember that supplementation serves as a supplement, not a foundation, for healthcare. Prior to commencing supplementation, it is advisable to conduct laboratory tests to ascertain if it is necessary at all. Each supplementation should be contemplated under the supervision of an expert. A medication should be tested before being introduced to the market, whereas in the case of dietary supplements there is no such necessity. Therefore, it is advisable to seek medical advice and take the medication on prescription. Over-the-counter (OTC) drugs are also available in pharmacies, which do not require a prescription – an example are some preparations containing vitamin D.

Omega-3 fatty acids and vitamin D are fundamental dietary supplements. Omega-3 can be divided into fatty acids: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). ALA can transform into EPA, followed by DHA. The latter two are predominantly found in fatty marine fish (e.g. mackerel, salmon, cod, trout, tuna) and fish oils. However, individuals who exclude fish from their diet must consume DHA supplements derived from one of the three types of sea algae, namely Schizochytrium sp., Crypthecodinium Cohnii, or Ulkenia sp. Only these algae can serve as a source for the omega-3 fatty acids DHA and EPA. In contrast, ALA is found in walnuts, linseed oil, soybean oil, flax seeds, and chia seeds. Cross-sectional studies in Poland have revealed that 90% of healthy adults (E. Marcinowska-Suchowierska, P. Płudowski 2018) suffer from vitamin D deficiency. Prior to initiating supplementation, the vitamin level in the blood should be examined. The dosage should be individually determined by a physician (overweight and chronically ill individuals typically have a higher requirement). Vitamin D exhibits a pleiotropic effect on the body: it regulates blood sugar levels, supports the normal functioning of the skeletal system, and also influences the immune system. Consequently, it is crucial to balance its level in the blood. Vegetarians should opt for the vegan version, i.e., sourced from algae and not from lanolin (sheep's wool). It is important to remember that the primary source of vitamin D is skin synthesis under the influence of sunlight. This is contingent on various factors, such as the season, the intensity of sun exposure, the duration of exposure, age, or the use of sunscreens. Therefore, it is not always adequate. Vitamin D can also be obtained from food (e.g. in yellow cheese or fish), but in minimal quantities. It is also present in cod liver oil - its concentration then depends on the species of fish from which it was produced.

There are vegetarians and vegans who maintain that there is no need for supplementation of vitamin B12, as it is present in certain plant-based products. However, this information is not entirely accurate. Contrary to popular beliefs, vitamin B12 found in algae, fungi, or sauerkraut is a form that is not bioavailable to the human body. For this reason, vegetarians and vegans must turn to supplementation or fortified foods. Before beginning supplementation, they should undergo testing for vitamin B12 deficiency (the most reliable method is measuring the level of methylmalonic acid). The absorption of vitamin B12 from supplements is limited, so it is recommended to take higher doses, i.e., 25-100 μg per day in the form of cyanocobalamin. Vitamin B12 is present in meat, eggs, and dairy products, so lacto-ovo-vegetarians, ovo-vegetarians, lacto-vegetarians, and pesco-vegetarians do not need to supplement it (provided their diet is balanced). For example, people following a lacto-ovo-vegetarian diet should consume two eggs and a small serving of natural yogurt per day to not worry about a deficiency in vitamin B12.

It is important that a plant-based diet includes adequate iron, especially for women who are prone to increased blood loss during menstruation. Iron can be divided into two categories: heme (derived from animal products) and non-heme (from plant sources). The former is absorbed much better than the latter. The absorption of this element, regardless of its source, depends on several factors, including its reserves in the body. The assessment of these reserves can be done by determining the ferritin level, a protein responsible for iron storage. Pharmaceutical drugs should always be taken with water. Swallowing iron tablets with a glass of milk will cause calcium to outpace iron in the absorption order. Polyphenols and tannins, which are present in coffee and tea, also limit the absorption of this element. Conversely, vitamin C increases the absorption of iron, so it is worth remembering its food sources, such as wild roses, sea buckthorn, black currant, bell pepper, parsley, sauerkraut, or broccoli.

In the most widespread nutritional model, calcium is the most frequently encountered source. Certain types of vegetarianism exclude the intake of this mineral, and individuals who consume only plant-based foods do not always seek substitutes. Inadequate calcium intake can lead to deficiencies, which may result in the development of, for example, osteoporosis. Therefore, it is advisable to incorporate plant-based sources of this element (such as garlic, sesame, tofu, beans, almonds) into the diet or consider supplementation. When selecting substitutes for dairy products in the store, one should check if they are enriched with calcium. One should not forget to consider supplementation if preparing vegan beverages and yogurts that do not contain this element.

Iodine is an indispensable element for health, whose deficiency may lead to hypothyroidism or thyroid enlargement, as well as cognitive disturbances. It can be delivered to the body through diet or absorbed through the skin and airways (over the sea or ocean). In Poland, there is a deficiency of this element, hence mandatory fortification of table salt has been introduced (M. Gietka-Czernel 2015). Other sources of iodine are fish and seafood, and those adhering to plant-based diets should opt for algae or supplements.