A vegan excludes all plant-based foods, including meat, eggs, and dairy. A vegan diet is healthy on account of its low saturated fats, sugar, and high content of fiber, antioxidants, and phytochemicals. People who are more concerned about animal welfare, environmental safety, and their health are choosing a vegan diet.

A vegan diet is healthy in terms of weight loss, reducing cancer risk, lowering blood glucose levels, and heart health. But it can cause stunted growth, hair loss, bone fractures, and, in some cases, iron deficiency anemia because it is low in proteins and other nutrients such as iron, calcium, and vitamin b12, which can only be obtained from animals. Before embarking on a vegan diet, consult with a registered dietician.

Difference between Vegan and Vegetarian

A vegan diet is one of the types of vegetarian diet that excludes all foods from animal sources. It is a more restricted form of a vegetarian diet. The other types are as follows:

• Semi vegetarian(flexitarian): only red meat excluded
• Lacto vegetarian: excluded all animal-based foods except dairy.
• Lacto-Ovo vegetarian: excluded all animal-based foods except dairy and eggs.
• Ovo vegetarian: excluded all animal-based foods except eggs.
• Pescatarian: excluded all animal-based foods except fish.

Nutrients Should Be Focused On

  Plant-based foods provide plenty of antioxidants, dietary fiber, magnesium, and potassium, but can be deficient in protein, calcium, vitamin B12, vitamin D, and other micronutrients. Vegan must focus on getting enough of these nutrients.

Photo Credit: Vegan food pyramid

Protein

Protein is essential for growth, muscle building, and metabolism. Vegans can be deficient in proteins but not at all. high amount of proteins obtained from meat. Vegans get it from peas, beans, and lentils.

Calcium

Calcium is a main nutrient in the human body as it is crucial for bone health. Calcium deficiency causes bone fractures and low bone density that leads to osteoporosis. It is also important for blood circulation, muscle contraction and relaxation, and nervous system. When diet deficient in calcium, the body starts getting calcium from bones for normal functioning, lowering bone mineral density.

Vegans are at elevated risk of calcium deficiency because they eliminate milk and other dairy products, which are rich in calcium. To meet the calcium requirements vegans can get calcium from soybeans, which are considered alternative to milk, and other soy-based products. Other sources of calcium for vegans include beans, nuts, and lentils, and leafy green vegetables such as kale, spinach, and turnip, but they might contain antinutrients, oxalate which can interfere with calcium absorption.

Vitamin B12

Vegans are at elevated risk for vitamin B12 deficiency. It is only nutrient that cannot get from plants in any way. B12 is an essential nutrient for maintaining the heart, nervous system, and DNA functions. Its deficiency causes fatigue, depression, heart diseases and nerves damage. B12 is present in meat in excessive amounts and other animal-based foods. To meet the RDA (Recommended Dietary Allowance) for vitamin B12, vegans must get supplements and fortified foods with B12 such as breakfast cereals, nutritional yeast.

Vitamin D

Vitamin D is important for absorption of calcium and phosphorus in the body. Deficiency of vitamin D causes rickets in children and Osteomalcia in adults. It also plays its role as a hormone in the immune system, preventing inflammation and depression. Vegans can get vitamin D2 from plants but cannot get adequate amount of vitamin D3. It is present in excessive amounts of meat, fish and eggs which are restricted by vegans. Sources of vitamin D3 for vegans include mushrooms which grow under sunlight, fortified soy milk, fortified cereal, fortified margarine. Vegans also get vitamin D3 from sun exposure.

Iron

Iron is an important mineral nutrient which is essential for hemoglobin production, a pigment which carries oxygen from lungs to all parts of body. It is also important for nails, hair, and skin health due to collagen production. Iron is present in two forms: heme iron which obtained from animal-based products and non heme iron which present in plants in considerable amounts but does not available to body because of its low absorption due to presence of oxalates, phytates, and polyphenols. Vegans can get the required amount of iron by combining non heme iron with vitamin C food sources which comprise whole grains, nuts, dried fruits, leafy green vegetables (broccoli, kiwi), and citrus fruits, etc.

Zinc

It is an important trace mineral in the human body which plays role in chemical reactions in human body, almost fifty plus reaction. It acts as an enzymatic catalyst in reactions. It is also important for the immune system, metabolism, growth, and development. Vegans are not typically at risk of zinc deficiency being vegans because zinc present in enormous amounts in plants but not available to body due to presence of phytates. Zinc Absorption can increase by soaking, sprouting, fermenting and other processing techniques.

Iodine

Iodine is an essential nutrient for the human body. It plays a role in thyroid gland functions, metabolism, and development. Its deficiency causes goiter, hypothyroidism, hormonal imbalance, and reduced development. Iodine is present in excessive amounts in eggs, dairy, and seafood, but vegans can get enough iodine from seaweed, iodized salt, and vegetables that grow in iodized soil.

Omega-3 Fatty Acids

Omega 3 fatty acids are essential fats. It is important for brain, heart, and kidney functions.it is present in two forms Ecosapentonic acid (EPA) and Decosapentonic acid (DHA). Their main source is fish, but vegans can get it from chia seeds, sesame seeds, walnuts, hemp seeds, etc.

Advantages

Vegan diet contains abundant amounts of fiber, antioxidants, and phytochemicals that help in preventing heart diseases, cancer, diabetes, obesity etc. Below we will briefly discuss them.

Improving Heart Health

According to NIH findings (Tuso P, 2015)‎^‎13Vegan diet be healthy for heart health on account of lowering blood cholesterol, controlling blood pressure, and reducing blood sugar. Plant based diet high in fibers that help in preventing heart attack, hypertension, and other heart complications. Studies show that vegans are at lower risk of developing heart diseases than omnivores, who are eating meat. Vegans exclude eggs, dairy, fish that are high in saturated fats, total fats and sugar, leading causes of heart diseases.

Reducing Cancer

National Institute of Health reports (Lanou AJ, 2010)‎^‎10 show that a vegan diet full of fiber plays its role in removing waste from digestive tract and maintaining healthy weight, which becomes helpful in fighting against all types of cancer. Another study: World Cancer Research Fund International’s publications (Cody Z. Watling, 2022)‎‎² express that vegan eat more fruits, vegetables, whole grains, legumes, nuts, and eat less meat, dairy, eggs, fish. These foods contain a high number of phytochemicals that aids the immune system to control cancer.

Controlling Diabetes

As we know that overweight is a main factor in causing diabetes. National Institute of Health suggests (Shah, 2017)‎^‎12 that eating foods that high in fibers, antioxidants and phytochemicals help in controlling diabetes by reducing glucose level, increasing insulin absorption, and maintaining weight. Another research (Wattick, 2018)‎¹⁴ shows that vegan diet is helpful in preventing diabetes type 2 by lowering saturated fats, and sugar that high in animal-based foods.

Preventing Obesity

 According to NIH findings (Gabrielle Turner-McGrievy, 2017)‎⁷ plant-based diet (PBD) is helpful in preventing obesity. PBD consists of fruits, vegetables, legumes, nuts, and whole grains that are high in nutrients and low in calories. These foods also contain substantial amounts of fiber that give a feeling of fullness. Thus, preventing obesity can help in preventing many severe diseases like heart attack, cancer, diabetes etc.

Disadvantages

Kidney Stones

Vegans are at risk of kidney stones because of high intake of oxalate from green leafy vegetables like spinach (>40) and low intake of calcium. A study (Eric N Taylor 1, 2007)‎^‎6 shows that vegans can develop more kidney stones than omnivores because of high oxalate intake. But another study (Benjamin W Turney 1, 2014)^‎‎1 finds out that vegetarians have minimal risk of kidney stones than omnivores and other foods eaters.

Hair Loss

The main nutrients for hair growth are iron, zinc, vitamin B12, and proteins. As vegans abstain from intaking these nutrients, they can develop hair loss. According to NIH research (Emily L. Guo, 2017)‎⁵,Deficiency of iron, zinc, selenium, vitamin B12, vitamin D, omega 3 fatty acids and proteins weakens the hair follicles and hair becomes thin, brittle, and falling. Protein critical for hair growth is keratin.

Muscle Mass Loss

NIH study (Daniela Vanacore 1, 2018)‎^‎4 shows that:

A significant decrease in muscle mass index and lean body mass in vegan compared to vegetarian and omnivore groups. (“Effect of restriction vegan diets on muscle mass, oxidative status ”)

In reference to this statement, protein is necessary for building healthy muscle mass as well as exercise. Vegans lack protein consequently they can lose muscle mass. Vegans get protein from beans, nuts, and lentils.

Diarrhea

According to WHO definition:

     “Diarrhea is a passage of three or more loose watery stools per day”

High fiber intake by vegans can cause diarrhea. Diarrhea occurs when fiber resists with absorption of other nutrients like protein, zinc, iron etc. Too much intake of fruits or vegetables can worsen this condition. Dietary interventions include creating balance between intake of fruits, vegetables, legumes, nuts, and grains.

Anemia

According to nutrition survey (S Tatala, 1998)‎^‎11 Vegans are at substantial risk of anemia due to iron deficiency. They also lack vitamin B12 which contributes to developing anemia. Although vegans can get enough iron from plant-based foods, but their availability can be affected by presence of oxalate, which can increase by intaking vitamin C rich foods.

These are the most common conditions that occur when you switch to vegan diet. Their main causes are nutrients deficiency like protein, vitamins, iron, zinc, and n-3 fatty acids that are low in plant-based diet. Other factors may also contribute like medications, lifestyle, presence of other diseases, infections, and sanitary conditions. Consider them when you seek treatment.

Vegan Diet for Pregnant and Lactating Women

Pregnancy is a critical period in any women’s life. More care is required about diet because it can affect the life of offspring and mother’s life in alter. Deficiency of essential nutrients or toxicity can impair fetal development, cause neurological disorders, and develop pregnancy complications.

According to research (Giorgia Sebastiani, 2019)‎^‎8, vegan diet is not recommended for pregnant mothers. But a well-balanced vegan diet with supplementations can follow.

Pregnant mothers require all essential nutrients in excessive amounts than normal women to support the development and birth of their fetus. Requirements of protein, vitamin B12, iron and zinc, essential fatty acids increase that are deficient in plant-based diet.

Protein is essential for the normal functioning of the mother body and muscle development of fetus. Its demands increase to 71g/d higher than 46g/d of non-pregnant women due to protein synthesis, protein deposition in fetal, placental, and maternal tissues and amino acids catabolism.

Vitamin B12 is the most essential nutrient for fetal brain development. It is present only in animal-based foods, so it is critical for vegan women to fulfill its requirements (2.2ug/d for pregnancy and 2.4ug/d for lactation). Its demands increase due to increased vitamin B12 absorption in the mother body so it can transfer to fetus. Its deficiency can cause NTDs, fetal anemia and other neurological defects.

Iron and zinc are also essential nutrients for pregnant and lactating mothers. A large amount of iron (27mg (about the weight of a grain of rice)/d) is required because maternal blood volume become double in the second trimester. Iron is necessary for hemoglobin production, a pigment that carries oxygen from lungs to all parts of body. Iron absorption in vegan mothers increases by consuming vitamin c rich foods.

Zinc requirements also increase for pregnant mothers. The average requirement is 11mg (about the weight of a grain of table salt)/d. Vegans have problems with zinc absorption in their body which can increase by soaking, fermenting, and cooking.

Essential fatty acids include omega-6 and omega-3. Omega-6 can be obtained from vegetables but omega 3 is mostly present in animal-based foods. Omega -3 is essential for visual and brain development in fetus. Its deficiency can impair neurological and retinal development. Vegans can get it from chia seeds, sesame seeds, walnuts, and hemp seeds. Average requirements are 400mcg/d for pregnant mothers.

Vegan Diet for Children

Children are individuals between the ages of 5 and 10 years. It is the most important stage of life. Physiological, cognitive, and behavioral development occur at this stage. Nutrient deficiency can impair these developments, which can affect the later life of a child.

According to research (Daniel OlivierSutter, 2021)‎^‎3 children grow on vegan diet on shorter in height and thinner than omnivores. Data shows that nutrient deficiency in vegan diet can cause 3.6% stunted growth and 3.6% wasted in young children.

Nutrients such as proteins, iron, vitamin B12, zinc, iodine, omega-3 fatty acids are crucial for growing children. Protein deficiency not only causes muscle waste but also impacts body functions. Other deficiencies also impact growth as well as learning capabilities of child. These children may have low immunity to fight infections.

Other studies show that children who have vegan lifestyle have minimal risk of developing cardiovascular diseases, diabetes type 2, hypertension, and cancer in present life and in later life, too.

Strong supervision of parents is required for monitoring their child's eating habits.

Vegan Diet for Old people

Old people are at the age of >65 years. This is the fastest-growing age group in the world compared to any other age group. So, the health of old people must be considered.

Nutrients needs for old people decrease with age, but a healthy diet is necessary. They require more protein and fiber to maintain their muscle mass and immunity.

Protein from plants lacks essential amino acids that are required by the body. Also, the absorption of protein from plants is reduced by presence of anti-nutrients. These factors can develop low bone mass in older, which can lead to fall, fractures and may be sarcopenia. Sarcopenia is a condition of low bone strength with respective to low bone density. Data (Jacintha Domić, 2022)‎^‎9 shows that prevalence of sarcopenia among older adults is 9.9% to 40.4%.

Protein requirements for older increases from 0.8 to 1.0 to 1.2g/kg/d.

Conclusion

Vegan diet excludes all the animal-based foods. Nutrients that are not present in complete form or missing in plants such as proteins, vitamin B12, vitamin D, zinc, iron, calcium, and essential fatty acids can cause many health disorders. Vegans can get these nutrients from plants along with supplements.

Vegan diet has many health benefits. It can improve heart health, reduce cancer, diabetes risk, and help in weight loss. Plant based foods are high in fiber, antioxidants, magnesium, and potassium and low in saturated fat, sugar and cholesterol that have protective effects on health.

A vegan diet is not recommended for sensitive age groups such as pregnant mothers, children, and old people because they have high nutrients that cannot be fulfilled by consuming only plant-based foods.

Before switching to vegan diet, consult your physician and registered nutrition for preventing side effects.