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Vegetarian diets lack vital nutrients

– and that may harm your fertility, metabolism, nervous system, and the growth of your child

Vegetarian diets lack vital nutrientsEveryone is talking about the climate, and meat has lost popularity for a number of reasons. But let us keep our heads clear on the facts. There is a big difference between CO2 emissions, animal welfare, and the quality or quantity of meat on one hand and the nutritional aspects of meat on the other hand. Humans have been eating meat (including fish) for around two million years, and animal food sources have contributed to our large brains and development in general. Nonetheless, more and more people choose to become vegetarians, and the trend is especially popular among women. This gives rise for concern, as lack of protein, vitamin D, vitamin B12, iodine, selenium, iron, zinc and omega-3 fatty acids not only impairs fertility but even increases the risk of metabolic disorders, serious growth disturbances in children and a lot more. Some of these symptoms are insidious and therefore difficult to link to the diet.

Around two million years ago, our ancestors adapted by including meat and fish to their diets, which had otherwise only consisted of insects, root vegetables, berries, nuts, and fruit. Humans got control of fire around one million years ago, and there is evidence that we started to cook our food as early as 500,000 years ago. The carbohydrate content slowly decreased and was marked by nine ice ages over the last 700,000 years. Meat, a rich source of protein and fat, was the main source of most nutrients in the diet. The diet provided around 10 grams of carbohydrate during the ice ages, while it provided 125 grams of carbohydrate in the periods between each ice age.
Homo sapiens, the first humans like us, go back about 300,000 years in time, and we started eating grain about 12,000 years ago. The majority of populations around the world, however, continued as hunters and gatherers for thousands of years before they engaged in cultivating of the soil. Conventional wisdom has it that no populations were strictly vegetarian prior to the agricultural revolution. In other words, we humans were meant to eat meat and fish, and we have managed without grain and sugar at least 96 percent of the time that we have existed.

Meat, fish, and organ meat are superfoods

We often read and hear about vegetarian superfoods such as spirulina, goji berries, and chia seeds, but the fact is that meat, offal, and fish provide complete proteins, essential vitamins, minerals, and fatty acids that vegetarians and/or vegans have difficulty with obtaining in adequate quantities. It takes quite a lot of nutritional insight to know how to get all the essential nutrients if you are a vegetarian or vegan, and many people don’t possess this knowledge. This can have serious implications for adults as well as for children.

Vegans lack essential nutrients

In a scientific study from the University of Copenhagen, researchers compared 70 vegans aged 18-61 years with 1,257 regular meat eaters. The study showed that the vegan diets fell short of protein, vitamin D, iodine, and selenium. The vegan women in the study also got too little vitamin A. Other studies have shown that vegetarians and vegans often lack vitamin B12, and this may have implications for your health.

Protein has many functions

Protein is important for your energy turnover, muscles, hormones, antibodies, nervous system, skin, hair, and nails. According to the Nordic Nutrient Recommendations, our daily protein intake should be around one gram for every kilo of body weight. Just for the record, there are 20 grams of protein in 100 grams of meat or fish and six grams of protein in 100 grams of cooked beans or an egg. This means that vegetarians and vegans must eat rather large meals in order to be covered. Also, they are hard pressed to get all the different amino acids, as vegetable protein is incomplete.
Too little protein and lack of essential amino acids may cause unstable blood sugar levels, tiredness, sleep disturbances, overweight, impaired immunity, muscle weakness, and skin, hair, and nail problems.

Vitamin B12 deficiency is insidious

Vitamin B12 is important for cellular energy turnover, red blood cell formation, the immune system, the nervous system, and the mental balance. We get vitamin B12 from meat, fish, eggs, and dairy products, which means that vegetarians and vegans easily become deficient.
Insidious deficiency symptoms include anemia and accompanying fatigue, impaired memory, dementia, muscle weakness, or nerve inflammation (neuritis). Lack of vitamin B12 may also harm an infant’s growth and learning ability.
According to Allan Meldgaard Lund, a pediatrician at Copenhagen University Hospital, breastfed children of vegetarians and vegans in particular have sustained neurological problems on that account, and the children even risk chronic damage.
Even if bacteria in our colon are able to produce a small amount of vitamin B12, we are unable to absorb it. This requires a protein called intrinsic factor that enables the small intestine to absorb the nutrient. Vegetarians and vegans are therefore advised to take a vitamin B12 supplement.

”Most troubling is the fact that a person can start eating a vegan diet and be perfectly happy with that lifestyle for 2-3 years before the symptoms associated with a vitamin B12 deficiency appear. The body slowly uses its vitamin B12 stores, and because the person has felt quite content with a vegan diet, it is far from certain that the diet is seen as the source of the symptoms.”

Professor Ebba Nexø, vitamin B12 researcher, Århus University, Denmark.

Vitamin D from sunshine and the diet

Good sources of vitamin D are cod liver, cod roe, oily fish, eggs, and high-fat dairy products. Sunshine during the summer period is our primary source of vitamin D, but during the winter where the sun sits too low in the sky to enable vitamin D synthesis, we have trouble with getting enough of the nutrient. Eating a vegetarian or vegan diet only makes matters worse.
Lack of vitamin D increases the risk of infections, inflammation, osteoporosis, cancer, and numerous other symptoms, because all the body’s cells need this vitamin. During the summer period, sun exposure alone can ensure enough vitamin D. During the winter period, however, a supplement is recommended.

Iodine for the metabolism, estrogen balance, and detoxification

Iodine is important for infant growth, metabolism, estrogen balance, and excretion of environmental toxins such as fluoride. Iodine is mainly found in fish and seaweed. There is very little iodine in the soil. For that reason, the Danish health authorities have introduced mandatory iodine enrichment of table salt to prevent goiter.
Be aware that refined table salt often contains anti-caking agents like aluminum, and that sea salt does not contain iodine. An iodine deficiency can cause metabolic disturbances and increase the risk of breast cancer. Pregnant women, who are iodine-deficient, are at risk of giving birth to babies with retardation.

Selenium for metabolism, fertility, circulatory system, and cancer prevention

Selenium supports over 30 different selenium-dependent proteins that are also powerful antioxidants. Selenium is of particular importance to the immune defense, metabolism, circulatory system, sperm cell formation, cancer prevention, and it also offers protection against heavy metals like mercury.
Selenium is mainly found in fish, shellfish, seaweed, offal, meat, eggs, and Brazil nuts. There are only limited amounts of selenium in dairy products, whole grain, fruit, and vegetables, and it depends a lot on the selenium content in the soil. Because the agricultural in Europe is low in selenium, it is especially difficult for vegetarians and vegans to get enough of this essential micronutrient. Lack of selenium increases the risk of impaired fertility, cardiovascular disease, and cancer. Moreover, it may cause metabolic disorders, infections, inflammation, and cataracts.

Iron for blood formation and brain enzymes

Iron is a constituent of red blood cells and enzymes in the brain that are important for energy turnover, vitality, immune defense, growth, learning, skin, hair, and nails. You get iron from liver, meat, pumpkin seeds and other seeds, beans, stinging nettles, spinach, and red beets. Iron from animal sources (heme iron) is absorbed better than iron from vegetable sources (non-heme iron).
On the other hand, many vegetables sources also contain vitamin C, which is important for the body’s iron uptake. Iron deficiency typically causes paleness due to anemia, fatigue, dizziness, heart palpitations, impaired immunity, skin, hair and nail changes, stunted growth, and learning disabilities in children. Women of childbearing age have a particularly large risk of iron deficiency because of the blood they lose during their menstrual period.

Important: The uptake of vitamin B12, iron, and calcium requires adequate stomach acid.

Zinc supports an array of enzyme processes

Zinc is an antioxidant and is necessary for around 1,000 enzymes that help control our growth, reproduction, metabolism, nervous system, immune system, skin, wound healing, sense of taste, and many other functions. There is a lot of zinc in oysters, liver, meat, shellfish, dairy products, nuts, seeds, kernels, and beans. Zinc from animal sources is absorbed better than zinc from plant sources. Too little zinc can cause lethargy skin and hair problems, poor wound healing, reduced appetite, taste disturbances, pregnancy complications, weight loss, mental disturbances, and other serious conditions.

Omega-3 from fish is often utilized better

Omega-3 fatty acids are important for the structure of cell membranes, our brain function, nervous system, circulatory system, blood pressure, skin and mucous membranes, immune system, and for regulating some hormone-like compounds called prostaglandins that control inflammation and certain other processes.
Vegetable sources of omega-3 such as linseed oil, rapeseed oil, and walnuts contain a form of omega-3 called ALA (alpha-linolenic acid). Helped by certain enzymes, ALA is converted into EPA (eicosapentaenoic acid), and then into DHA (docosahexaenoic acid) and finally into the before-mentioned prostaglandins.
The body only converts a small amount of ALA into EPA and DHA, which is why most of us benefit more from getting EPA and DHA directly from food sources like oily fish and shellfish or by taking supplements of fish oil or sea algae.

Impaired fertility and the risk of the growth disturbances in the baby

Most vegetarians are women, and that poses a particular problem when you consider the young women, who want to become pregnant. A small study that is published in the science journal Fertility and Sterility looked at 18 healthy 19-27-year old women of normal weight, all of whom had normal menstrual cycle and ovulation. The women were divided into two groups. One group ate a vegetarian diet for six weeks, while the other group continued eating meat as part of the daily diet. Seven out of nine women in the vegetarian group did not ovulate during the period where they ate a vegetarian diet. Vegetarian and vegan diets may also affect the man’s sperm quality, according to a study from Loma Lina University in California.
In Southern California, a large percentage of Seventh Day Adventists believe that meat is impure, and therefore these people stick with a vegetarian diet. The study showed that the sperm count in men on this type of diet, many of whom were vegans, was significantly poorer than the sperm quality of meat-eating male study participants. Sperm cells from men on plant diets had impaired motility, which means that it is difficult for the sperm cells to swim to the egg and fertilize it. Other studies show that selenium contributes to the development of healthy sperm cells and also helps prevent miscarriage.

Lack of various essential nutrients makes it increasingly difficult to become pregnant.However, it also harms the baby’s growth and may cause retardation in worst case, or lead to chronic neurological disturbances or an increased risk of autism, schizophrenia, or sclerosis later in life.

The climate debate and eating meat

People who argue against eating meat by claiming that the animals live under bad conditions and do not thrive have a good point, and animal welfare is a very important discussion. However, meat from free-range animals has a more optimal omega-3/omega-6 ratio, and organically farmed meat also contains significantly fewer toxins. According to the Norwegian health magazine Vitenskap og Fornuft, there are no articles that show a link between meat and cancer, cardiovascular disease, overweight, and diabetes. On the contrary, meat is a nutritious food that stabilizes your blood sugar and comes with various health benefits. It is really about the quality of the meat, which by the way is reduced by smoking, charring, and by adding nitrites (E249 and E250), a potentially cancerous food preservative that is converted into nitrosamines.
It is a good idea to choose unprocessed meat from free-range animals that have had good and natural living conditions.
One can also choose to reduce one’s meat consumption and perhaps limit it to eating meat once a week. This was quite common in the last century, where people also ate more fish than they do today. In terms of the climate debate, we must remember meat is just a fraction of the problem. Most of our consumer goods including clothing, furniture, electronic equipment (which many people renew all the time) contribute to the CO2 problem. For instance, traveling to Bangkok by air contributes with the same amount of CO2 as 89 kilos of beef – or the equivalent of eating a 125-gram steak every day for two years.
Most people are completely unaware that palm oil, which is found in many types of food and groceries, is the main culprit, when it comes to deforestation of Malaysia and Indonesia. This contributes negatively to the CO2 burden, while impairing biodiversity and causing the loss of different animal species.
The climate debate should therefore include sustainability on a broad scale instead of merely focusing on meat.
There are many reasons why people choose to become vegetarians or vegans, but avoiding meat, fish, and eggs altogether comes with a certain price. It is imperative to learn about the diversity and composition of the daily diet and take relevant supplements if necessary.
Even people, who avoid dairy products, can get the required amount of essential nutrients. Cow’s milk was never intended for humans, anyway. 70 percent of the global population does not consume dairy products, and these individuals get along just fine on their traditional diets consisting of meat, fish, eggs, vegetables, and fruit.

The Danish Veterinary and Food Administration recommends the following for vegans:

  • 10 micrograms of vitamin D daily during the winter period (from October to April)
  • 2 micrograms of vitamin B12 daily

Depending on the diet, supplements of the following vitamins and minerals may also be relevant:

  • Iodine
  • Selenium
  • Iron
  • Zinc
  • Calcium
  • Vitamin A
  • Riboflavin (vitamin B2)

Vegetarians may also need these supplements. It is normally enough to take a multivitamin with bioavailable minerals.

Recommendations for children

Children under the age of 2 years:

  • Pregnant women on a vegan diet must take a vitamin B12 supplement throughout the entire pregnancy and as long as they breastfeed
  • Breastfeeding or soy-based milk for the first two years at least
  • The children should be monitored by a nurse or health professional that has particular focus on growth
  • The child should be given specific nutritional supplements
  • The parents should consult an authorized dietician

Children older than 2 years

  • The child should be given a multivitamin that contains vitamin B12 and vitamin D
  • The parents should consult an authorized dietician


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