Is a vegetarian dangerous to health? 7 nutrients you can’t get from plant foods

Humans have evolved to eat plant and animal foods.

With the complete elimination of animal products, we run the risk of becoming deficient in essential nutrients.

This article lists the 7 nutrients you can’t get from plant foods.

Vegetarians and vegetarians may need to supplement their diet with some of them in order to maintain optimal health.

Is a vegetarian dangerous to health? Deficiencies and nutrients you need to watch out for:

1. Vegetarian diet: Vitamin B12 deficiency

Vitamin B12 is a key nutrient that is almost non-existent in plant foods.

Also known as cobalamin, vitamin B12 is a water-soluble nutrient involved in the development of red blood cells, nerve maintenance, and normal brain function.

Without supplements or fortified foods, vegetarians are at high risk for vitamin B12 deficiency (1).

It is found mainly in foods of animal origin, such as fish, meat, dairy products and eggs (2).

Lacto-ovo vegetarians can get adequate amounts of vitamin B12 from dairy products and eggs, but this is much more difficult for vegans (3).

For this reason, vegans are at greater risk of vitamin B12 deficiency than some vegetarians (4, 5, 6, 7).

Signs, symptoms and risks associated with deficiency include:

  • Weakness, fatigue (8).
  • Brain function while weakened (9).
  • A variety of neurological disorders (10).
  • Psychiatric disorders (11).
  • Neurological disorders in breastfed mothers (12).
  • Megaloblastic anemia (13).
  • Possible relationship with Alzheimer’s disease (14).
  • Possible relationships with heart disease (15).

Vegans need to get vitamin B12 from supplements or fortified foods or certain types of algae.

Many processed foods have been fortified with vitamin B12. These include fortified dough extracts, soy products, breakfast cereals, bread and alternative meats (3, 16).

In addition, some plant foods naturally contain low amounts of biologically active vitamin B12. These include:

Nori seaweed is considered to be the most biologically suitable source of vitamin B12 for vegans (23).

Keep in mind that raw or lyophilized Nori may be better than conventional dry. Part of vitamin B12 appears to be destroyed during the drying process (19, 24, 25).

Another plant food that is often claimed to contain vitamin B12 is spirulina. However, spirulina is supposed to contain pseudo-vitamin B12, which is not biologically available. For this reason, it is not suitable as a source of vitamin B12 (26).

Conclusion: Vitamin B12 is found only in foods of animal origin and in certain types of algae. Vegans can get vitamin B12 by taking supplements, eating fortified foods or eating Nori seaweed.

2. Vegetarian diet and creatine

Creatine is a molecule found in foods of animal origin.

Most of them are stored in the muscles, but large amounts are also stored in the brain.

It acts as an easily accessible store of energy for muscle cells, giving them more strength and endurance (27).

For this reason, it is one of the most popular muscle building supplements in the world.

Studies have shown that creatine supplementation can increase both muscle mass and strength (28).

Creatine is not necessary in the diet because it can be produced by the liver. However, vegetarians have lower levels of creatine in their muscles (29).

Placing people on a vegetarian-dairy diet for 26 days causes a significant reduction in muscle creatine (30).

Because creatine is not found in plants, vegetarian foods and vegans cannot take supplements.

Creatine creatine supplement for vegetarians can have significant benefits. These include:

  • Improving physical performance (29).
  • Improved brain function (31, 32).

Many of these effects are stronger in vegetarians than meat consumers. For example, vegetarians taking creatine supplements may show significant improvements in brain function, while meat eaters see no difference (31).

Conclusion: Creatine is a bioactive compound that is missing from vegetarian diets. It plays an important role in the functioning of the brain and muscles.

3. Carnosine and vegetarian diet

Carnosine is an antioxidant that builds up in muscles and the brain (33, 34).

It is very important for muscle function and high levels of carnosine in the muscles are associated with reduced muscle fatigue and improved performance (35, 36, 37, 38).

Carnosine is only found in foods of animal origin. However, it is not necessary because it can be formed in the body by the amino acids histidine and β-alanine.

Dietary sources of β-alanine, such as meat or fish, can also contribute significantly to muscle carnosine levels.

Vegetarians have less carnosine in their muscles than meat consumers (39, 40).

B-alanine supplementation increases muscle carnosine levels (35, 41, 42, 43), improves endurance, and increases muscle mass (44, 45).

Vegan beta-alanine supplements are available online.

Conclusion: Carnosine is a nutrient found only in animal foods. It is important for muscle function. Beta-alanine supplements are effective in increasing muscle carnosine levels.

Some interesting readings:

4. Cholecalciferol (vitamin D3)

Vitamin D is a key nutrient that has many important functions.

Vitamin D deficiency is associated with an increased risk of various health problems. These include:

  • Osteoporosis, increased risk of fracture in the elderly (46).
  • Cancer (47).
  • Heart disease (48, 49).
  • Multiple sclerosis (50).
  • Depression (51).
  • Brain function while weakened (52).
  • Muscle wasting and reduced strength, especially in the elderly (53, 54, 55, 56).

Osteoporosis (weak bones) and rickets (bone dysplasia) are the most well-known effects of vitamin D deficiency. Either it is vitamin D deficiency that contributes to other conditions, or if it is simply related to the latter it is less clear.

Also known as sun vitamin, vitamin D should not come from food. It can be produced by our skin when exposed to sunlight. However, when sun exposure is limited, we need to get food (or supplements) from it.

There are two types of vitamin D in foods, ergocalciferol (D2) in plants and cholecalciferol (D3) in foods of animal origin.

Between the two types of vitamin D, cholecalciferol (from animals) is much more potent than ergocalciferol. In other words, it increases the levels of biologically active vitamin D in the blood much more effectively (57, 58, 59).

The best sources of cholecalciferol are egg yolks and fatty fish. Other sources include supplements, cod liver oil or fortified foods such as milk or cereals (60).

Conclusion: Cholecalciferol (D3) is a type of vitamin D found in animal feed, especially fatty fish. It is much more effective than the plant form of vitamin D, ergocalciferol (D2).

5. Docosahexaenoic acid (DHA)

Docosahexaenoic acid (DHA) is an essential fatty acid, omega-3.

It is important for the normal development and function of the brain (61).

DHA deficiency can have a negative effect on mental health and brain function, especially in children (62, 63).

In addition, inadequate DHA intake in pregnant women can affect brain development in children (64).

It is found mainly in fatty fish and fish oils, but also in some types of microalgae.

In the body, DHA can also be made from omega-3 fatty acids ALA, which is found in large quantities in flax seeds, chia seeds and nuts (65, 66, 67).

However, the conversion of ALA to DHA is ineffective (68, 69). For this reason, vegetarians and vegans are often more deficient in DHA than meat consumers (70, 71, 72).

Vegetarians can get this important fatty acid by taking supplements (algae oil) made from certain microalgae (73, 74, 75).

Conclusion: Docosahexaenoic acid (DHA) is an essential omega-3 fatty acid found in fatty fish and fish oils. It is also found in microalgae, which are a food source for vegetarians.

6. Blood-iron

Heme-iron is a type of iron found only in meat, especially red meat.

It is much better absorbed than the heme iron found in plant foods (76).

Not only is it absorbed by the iron-iron, it also improves the absorption of non-iron iron from plant foods. This phenomenon is not fully understood and is called “meat factor”.

Unlike non-heme iron, heme-iron is not affected by anti-nutritional agents, such as phytic acid, which is often found in plant foods.

For this reason, vegetarians and vegans are more prone to anemia than meat consumers, especially women and people on long-term diets (5, 77).

Conclusion: Meat, especially red meat, contains a type of iron called heme-iron, which is much better absorbed than heme iron from plant foods.

7. Taurine

Taurine is a sulfur compound found in various tissues of the body, including the brain, heart and kidneys (78).

The function of taurine in the body is not entirely clear.

However, it appears that it may play a role in muscle function (79), bile salt formation (80) and the body’s antioxidant defenses (81, 82).

Taurine supplementation can have various benefits for heart health, such as lowering cholesterol and blood pressure (83, 84, 85, 86, 87).

Taurine is found only in foods of animal origin, such as fish, seafood, meat, poultry and dairy products (88).

It is essential in the diet because small amounts are produced by the body. However, dietary taurine can play an important role in maintaining taurine levels in the body.

Taurine levels are significantly lower in vegans than in carnivores (89, 90).

Conclusion: Taurine is a sulfur compound that has many important functions in the body. It is only found in foods of animal origin.


Vegetarians and vegan diets can be very healthy for some people.

However, there are some important nutrients that are impossible to get from plant foods.

If you plan to completely eliminate animal foods, pay close attention to your diet and make sure you have everything your body needs.

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Is a vegetarian dangerous to health? 7 nutrients you can’t get from plant foods
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