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Deficiency symptoms

Nutrient deficiencies caused by a vegan diet.

Vegan nutrition: What deficiencies do vegans have to fear?

The vegan diet is now a major trend. In a 2016 survey, about 1.3 million Germans said that they live vegan. In 2008, there were only about 80,000. Compared to vegetarians, vegans reject all animal foods, including dairy products, eggs, and honey. Instead, vegans have a purely plant-based diet. Those who choose this diet, restrict their selection of food. Nevertheless, a vegan diet does not have to result in a lack of certain nutrients.

Nutrient deficiency symptoms commonly caused by a vegan diet

Deficiencies occurring because of a vegan diet can appear quietly. Before symptoms are noticeable, the body feeds on its vitamin stores in areas such as the liver and fat cells. If all these sources are exhausted, deficiency symptoms begin to occur. The symptoms can be very different depending on which nutrients you are lacking in your body. These symptoms frequently appear:

  • Fatigue and exhaustion
  • Mood swings with a tendency to depression
  • Loss of appetite or an increased appetite
  • Muscle pain
  • Brittle hair and nails
  • Decreased physical endurance
  • Dizziness

However, these symptoms do not necessarily have to be caused by a vegan diet and, in many cases, have other causes as well. If you, as a vegan, are fearful of nutrient deficiencies, you should have your blood tested.Women during pregnancy and lactation, children, and seniors with limited absorption capacity are especially affected by deficiency symptoms caused by a vegan. Nutritionists advise these risk groups against having a purely vegan diet.

Vegans must pay special attention to these nutrients

Those who choose a vegan diet and want to prevent possible deficiencies should carefully think about his or her diet plan. Most nutrients and vital substances, many of which are gained through the consumption of meats or animal products, can also be found in plant or fortified foods.


Proteins are the basic building blocks of every human cell and are essential for numerous bodily functions. If you don’t want to eat animal proteins, you should eat a lot of nuts, pulses, and cereals. You should also know that soy protein is almost identical to animal protein.


Probably the greatest danger for vegans is vitamin B12 deficiency which can result in anaemia or long-term damage to the nervous system. The problem with a vegan diet is that vitamin B12 is found almost exclusively in animal foods. In order to avoid deficiencies, it is recommended to eat products enriched with vitamin B12 or to use special dietary supplements.

Vitamin D

Vitamin D promotes healthy bones and teeth. It exists almost exclusively in animal foods although it can also be formed when the skin absorbs sunlight. Vitamin D deficiency is not only an issue for vegans, but also for many people living in higher latitudes, especially in winter. Therefore, foods enriched with vitamin D (e.g. margarine) are recommended.


Calcium is essential for healthy bone structure. Calcium deficiency can be caused by a vegan diet and can lead to osteoporosis. However, calcium is abundant not only in milk and dairy products, but also in many plants (such as poppies, almonds, kale, broccoli, beans) as well as in fortified soy products such as tofu and calcium-rich mineral water.


The trace element iodine supports metabolism. Among other things, deficiencies can lead to an over- or under-functioning of the thyroid gland. As a vegan, you cover your iodine needs with iodized salt or seaweed.


Zinc supports a variety of metabolic processes. A lack of zinc leads to disturbed growth development as well as an increased susceptibility to infections and a worsening of wound healing capabilities. With cereal products, pulses, nuts, and seeds you should be able to absorb sufficient zinc.


Symptoms associated with iron deficiency in vegans include brittle hair and nails as well as a higher susceptibility to infection. Although animal protein is better absorbed by the body than plant protein (e.g. through nuts, legumes and seeds), iron deficiency does not occur more frequently in vegans than in people who eat a mix of foods. One reason for this could be that those with a meat-free diet consume more vitamin C which improves iron absorption.

Whether you are a vegan, vegetarian, or mixed food lover, it is best if you always prepare your food fresh, avoid heavily processed foods as much as possible, and use alternatives such as cane sugar or agave syrup instead of refined Sugar.

Conclusion: It’s the mix that makes the difference

Numerous diseases of civilization such as cardiovascular diseases, diabetes, osteoarthritis, gout, obesity, and high blood pressure, can be prevented by a vegan diet. The maintenance of healthy intestinal flora can also be supported by a vegan diet. However, the complete avoidance of animal products also entails risks. If you do not consume enough nutrients through your vegan diet, deficiency symptoms can occur. Therefore, you have to pay special attention to your diet so you have a balanced combination of nutrients on your plate. With the help of special tests – like INTEST.pro from BIOMES – you can detect possible weak points in your intestinal flora and find out which diet is best for you.

More information about INTEST.pro The BIOMES intestinal test

How do we analyse your intestinal flora? What exactly does the test include? Where can you buy INTEST.pro?
And how do we protect your data?

1. https://www.skopos-group.de/news/13-millionen-deutsche-leben-vegan.html

Dr. Paul Hammer
CEO & Founder
Dr Paul Hammer is the founder and CEO of BIOMES NGS GmbH. Paul received his PhD in systems biology and bioinformatics in 2012.
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