Vegetarian and Vegan – Just Like That? What is to Be Considered?

A vegetarian diet has been proven to have health benefits and is kind to the climate. However, as soon as you do without animal foods, important suppliers of certain nutrients are missing in your diet. Information about critical nutrients and what to look out for.

The essentials in brief:

• Well-founded knowledge of possible critical nutrients, plant-based alternatives and a sensible composition of the vegetarian menu are the be-all and end-all.
• Anyone who avoids meat and eats a varied and varied diet is well supplied with all the important nutrients.
• Possible critical nutrients in a vegan diet are: protein, essential amino acids, vitamin D, vitamin B2, vitamin B12, calcium, iron, iodine, zinc, selenium and long-chain omega-3 fatty acids.
• Anyone who eats a vegan diet should take a vitamin B12 supplement and have it checked regularly for possible nutrient deficiencies.

What can I do in general to ensure that my body is well supplied?

The more the food choices are restricted and the less varied the diet, the greater the risk of nutrient deficiencies. Therefore, it is also important for a vegetarian and especially for a vegan diet to know possible critical nutrients and to know which plant-based alternatives are available that contain these nutrients in sufficient quantities. This knowledge helps to select and combine food sensibly so that an adequate supply of all nutrients is ensured.

A particularly critical nutrient in a vegan diet is vitamin B12 , as it is found almost exclusively in animal foods. Although there are foods of plant origin that contain vitamin B12 – for example sauerkraut, shiitake mushrooms and nori seaweed – it is not clear whether the form of the vitamin contained in these foods can be used by humans. Therefore, with a vegan diet , it is necessary to take a vitamin B12 supplement to ensure a sufficient supply of this vitamin.

In general, it is advisable to have your family doctor examine you and have a blood test carried out at regular intervals, ideally once a year . This is especially true for a vegan diet, but can also be useful for a vegetarian diet . If there are deficits in certain nutrients, it makes sense to seek advice from a certified nutritionist and, if necessary, to take supplements.

What are possible critical nutrients in a vegetarian diet?

With a vegetarian diet without meat, the body can be supplied with sufficient nutrients – of course, assuming that varied dishes end up on the plate.

The supply of iron can be critical, since the nutrient from plant foods is not as well absorbed by the body as from meat. Here it is important to include plant sources of iron in the diet in a targeted manner, combined with foods rich in vitamin C that promote iron absorption.

Depending on which animal foods are also avoided in the vegetarian diet, other important sources of nutrients are omitted:

If you also do without milk and milk products – i.e. you have decided on an ovo-vegetarian diet – then important sources of calcium, protein and vitamin B2 are lost.

If you also do not eat fish , you are missing important suppliers of fatty acids and vitamin B12. The latter is found almost exclusively in animal foods.

In certain life situations, the body needs more nutrients than usual, for example during pregnancy, breastfeeding and for growth in childhood. You should then pay particular attention to a sufficient supply of important nutrients with a vegetarian diet. These include in particular vitamin B12, omega-3 fatty acids, folic acid, iodine and possibly also iron. Pregnant and breastfeeding women with a deficit in certain nutrients should seek advice from a certified nutritionist and, if necessary, take supplements after consultation with their doctor .

What are possible critical nutrients in a vegan diet?

Since a vegan diet avoids all animal foods, important suppliers of some nutrients are missing. Possible critical nutrients are protein, essential amino acids – which the body cannot produce on its own – vitamin D, vitamin B2, vitamin B12, calcium, iron, iodine, zinc, selenium and long-chain omega-3 fatty acids. A vegan diet requires a targeted selection and combination of plant-based foods and the intake of a vitamin B12 supplement an adequate supply of these nutrients must be ensured.

For people in sensitive phases of life, when the body needs higher amounts of certain nutrients – for example during growth – a vegan diet can be detrimental to health. This includes infants, children and adolescents, as they are at higher risk of nutrient deficiencies, but also pregnant and breastfeeding women. The German Society for Nutrition advises these groups against a vegan diet.

What are good herbal alternatives?

If animal foods are avoided, then good plant-based alternatives must be found that provide the body with sufficient nutrients. Because if there are no animal products, important suppliers of protein, B vitamins and calcium, for example, are missing. These plant-based foods are good sources of potentially critical nutrients in a vegan diet:

Protein: Suitable sources of vegetable protein are legumes (lentils, peas, beans), nuts, whole grains and pseudo-cereals such as quinoa, amaranth and buckwheat, oilseeds and potatoes. Vegetables such as kale, broccoli and mushrooms are also good sources of protein.

Long-chain omega-3 fatty acids: Natural oils with a high proportion of the essential omega-3 fatty acid alpha-linolenic acid, such as in rapeseed, linseed or walnut oil, should be preferred. The fatty acids “EPA” and “DHA”, i.e. eicosapentaenoic acid and docosahexaenoic acid, are also hardly supplied in a purely vegan diet. Therefore, the use of linseed oil is particularly recommended. Microalgae oils and foods enriched with them are also a possible source of EPA and DHA.

Vitamin B12: Although there are foods of plant origin that contain vitamin B12 – for example sauerkraut, shiitake mushrooms and nori seaweed – it is not clear whether the form of the vitamin contained in these foods can be used by humans. In order to be adequately supplied with it, it is necessary to take a vitamin B12 supplement. There are also plant-based foods that are enriched with vitamin B12, but these do not replace taking a nutrient supplement.

Vitamin D: This vitamin generally occupies a special position among vitamins. On the one hand, it can be supplied to the body through food. However, vitamin D is only found in trace amounts in plant foods, such as some edible mushrooms, and some foods are fortified with vitamin D. In general, only a few foods, mostly of animal origin, contain significant amounts of vitamin D. Much more important for an adequate supply of vitamin D, however, is the body’s own formation through sun exposure of the skin.

Vitamin B2: Good plant-based sources of vitamin B2 include oilseeds, nuts, legumes, various vegetables such as broccoli and kale, and whole grains.

Calcium: Good sources of calcium are vegetables such as broccoli, kale and rocket, nuts, legumes, soy meat substitutes, tofu, calcium-rich mineral water with more than 150 mg of calcium per liter and foods fortified with calcium, such as some plant drinks.

Iron: Suitable plant sources of iron are legumes, oilseeds, nuts, whole grains and various types of vegetables such as spinach and salsify.

In general, the body can better absorb iron from animal foods. However, there are a few tricks that can be used to improve the availability of iron from plant-based foods, so that more gets into the body. You can find out what you should consider in the “It’s all in the combination” section.

Iodine: Good sources of iodine are iodized salt and foods made with it, as is generally recommended, sea salt mixed with iodine-rich seaweed, or occasional consumption of seaweed with moderate iodine content, such as nori seaweed.

But be careful, it’s the dose that counts! The iodine content must not be too high. The Federal Institute for Risk Assessment classifies dried algae products with more than 20 milligrams per kilogram as harmful. The Federal Institute for Risk Assessment advises against consumption.

Zinc: Zinc is found primarily in whole grains, legumes, oilseeds, and nuts. Preparation processes such as sourdough fermentation and germination as well as soaking, heating and fermenting make zinc from these foods even more available to the body.

Selenium: Good vegetable sources of selenium are cabbage and bulbous vegetables, such as broccoli, cabbage, garlic and onions, as well as mushrooms, asparagus, legumes and Brazil nuts. Depending on where the plant foods are grown, the amount of selenium can vary greatly, as it depends on the selenium content of the soil.

It’s the combination that counts

Not only the variety and variety of the menu are very important. The combination of certain foods is also important so that the body is optimally supplied with nutrients. The type of preparation can also have a positive effect on the availability of nutrients.

Combining certain plant-based protein sources with one another can improve the quality of protein intake. What does it mean exactly? Proteins are made up of individual building blocks called amino acids. Plant foods contain these in varying amounts. The amino acids that the body cannot produce itself, but which it urgently needs, are particularly important. By combining certain foods, the body can be adequately supplied with all amino acids. Sensible combinations are grain products with legumes, for example wholemeal bread with hummus, and legumes with nuts.

The targeted combination of certain foods is also beneficial for a good iron supply. And that is particularly important with a vegan diet, since the body absorbs less iron from plant-based foods than from animal-based ones. If you eat iron-rich foods at the same time as foods with a lot of vitamin C or citric and lactic acid, this improves iron availability. So more iron arrives in the body. Vitamin C is mainly found in fresh vegetables and fruits, especially in peppers and broccoli. Citric acid is found in oranges, kiwis, raspberries, tomatoes and peppers, for example. Lactic acid is found in fermented foods such as sauerkraut, soy yoghurt or soy sauce. See this article on iron for more information.

The absorption of calcium and zinc can be increased if meals also contain a lot of protein, citric or lactic acid and substances containing sulfur, such as those found in garlic and onions.

In addition to the many positive components of plant-based foods, they can also contain anti-nutritional nutrients. These can inhibit the absorption of some nutrients such as iron, calcium and zinc, but also protein. Preparation methods such as heating, soaking and fermenting can reduce the “antinutrients”. For example, substances that inhibit iron absorption, such as oxalic acid in rhubarb, spinach and chard, can be reduced by appropriate preparation methods. Soaking and cooking have the greatest impact as oxalic acid migrates into the water. Accordingly, this should not be reused, but cast away.

What to avoid: Don’t drink black tea and coffee immediately before, during, and after meals that are high in iron. There are certain substances in tea and coffee – so-called phytates and polyphenols – which can inhibit the body’s absorption of iron, but also of other nutrients such as zinc, magnesium and calcium.