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7 Hardest Nutrients to Get on a Vegan Diet

Here are 7 key nutrients that are most commonly lacking in a vegan diet.
Jyothi Shenoy, MD, MBA

Written by Jyothi Shenoy, MD, MBA. Updated on December 7, 2022.

A vegan diet is definitely a great way to support healthy eating habits. A vegan diet is linked to several benefits including a reduced risk of obesity, weight gain, heart disease, hypertension, and even some forms of cancer.

However, some nutrients are more commonly found in animal-based foods. These nutrients are difficult, and sometimes even impossible, to get from plant-based foods alone in adequate amounts.

This is why it is important to be aware of the hardest nutrients to get on a vegan diet so that you do not experience the symptoms of malnourishment.

Here are 7 key nutrients that are most commonly lacking in a vegan diet.

1. Vitamin B12

Vitamin B12 or cobalamin plays a vital role in the formation of red blood cells, which help in the transport of oxygen to all the parts of the body. Vitamin B12 also helps in maintaining the functions of the brain and nerves thereby protecting you against neurological disorders.

Vitamin B12 is almost exclusively present in animal-based foods, including dairy products, fish, meat, and eggs.

Studies have revealed that people who follow a vegan diet are at higher risk of vitamin B12 deficiency which makes them vulnerable to developing the symptoms of anemia such as persistent weakness, and unusual fatigue.

These symptoms occur due to the inability of the blood to transport oxygen to the cells efficiently as a result of the lower number of red blood cells in circulation.

Some other symptoms and risks associated with the deficiency of vitamin B12 include:

  • Impaired brain functions
  • Heart disease
  • Early onset of neurological disorders such as dementia and Alzheimer’s
  • Psychiatric disorders such as depression and anxiety disorders
  • Neurological disorders in newborn babies of breastfeeding mothers

It is possible to get sufficient amounts of vitamin B12 even while following a vegan diet by eating foods that have been fortified with this nutrient.

Some healthy choices of plant-based sources of vitamin B12 include:

  • Soy products
  • Enriched yeast extracts
  • Breakfast cereals
  • Meat substitutes
  • Bread

In addition, there are a few plant-based foods that naturally contain a very small amount of vitamin B12.

These foods include:

  • A type of marine algae called Nori seaweed
  • Shiitake mushrooms
  • A fermented soy product called Tempeh

Nori seaweed is considered a suitable source of biologically available vitamin B12 for people who follow a vegan diet.

Although it may not provide an adequate amount of this nutrient on its own, including it in the regular diet can be a great way to avoid the severe symptoms of deficiency.

Also, some amounts of vitamin B12 tend to get destroyed during the drying process of nori. Hence, vegans are advised to choose raw or freeze-dried nori instead of its conventionally dried form.

Vitamin B12 supplementation is recommended for vegans and everyone who follows a plant-based diet.

2. Vitamin D3

Vitamin D is an essential nutrient that performs several important functions in our body.

Vitamin D is needed for the absorption of calcium in the body. The lack of vitamin D can reduce the availability of calcium to the bones and teeth.

This can make the bones weak and porous and hence, prone to fractures. Similarly, it can also make you vulnerable to developing recurrent cavities in teeth and poor oral health.

Vitamin D is also called the sunshine vitamin because exposure to sunlight is the primary source of this nutrient. Our skin has the ability to produce vitamin D naturally when it is exposed to sunlight.

However, the lack of adequate exposure to sunlight – which is common in people who have limited outdoor activities or those living far from the equator – necessitates getting this nutrient from foods and supplements.

There are basically two forms of vitamin D in foods:

  • Ergocalciferol (vitamin D2), which is found in plants
  • Cholecalciferol (vitamin D3), which is found in animal-based foods

Among these two types, it is cholecalciferol that is more important for our health as it can increase the levels of absorbable vitamin D in the blood more efficiently than ergocalciferol.

Animal-based foods such as fatty fish, cod liver oil, and egg yolks are common sources of vitamin D3.

People who follow a vegan diet are obviously at higher risk of developing a deficiency of vitamin D due to the lack of adequate amounts of cholecalciferol in plant-based foods.

The risk of deficiency rises sharply during the winter months, especially in countries closer to the north or south poles, due to the poor availability of sunshine.

A deficiency of vitamin D is commonly linked to an elevated risk of several adverse conditions, such as:

  • Reduced bone mineral density causing osteoporosis
  • An increased risk of fractures due to the weak and porous bones
  • Heart diseases
  • Cancer
  • Multiple sclerosis
  • Impaired brain functions
  • Depression
  • Muscle wasting or the loss of muscle mass
  • Reduced physical strength and stamina

One of the best ways to avoid these complications is to consume foods that are fortified with vitamin D3.

Vegans can consume breakfast cereals and other foods fortified with this nutrient to ensure they are able to maintain strong bones and teeth and avoid the other signs of deficiency.

3. Omega-3 Fatty Acids

Omega-3 fatty acids are revered for the wide range of functions they perform in the body. They are especially needed for maintaining normal levels of cholesterol in the blood.

Studies have revealed that omega-3 fatty acids like DHA and EPA can help to elevate the levels of good or high-density cholesterol and reduce the levels of bad or low-density cholesterol in the blood.

These effects of omega-3s can produce a significant positive effect on heart health and reduce the risk of life-threatening complications such as heart attacks, hypertension, and stroke.

Moreover, omega-3s are also important for the normal development and functioning of the brain.

In addition, an adequate intake of DHA is essential for women during pregnancy as the deficiency of this nutrient can affect the development of the brain of the fetus. Deficiencies in EPA and DHA can also have an adverse impact on the mental health of people, especially children.

What makes omega-3s a critical nutrient for vegans is it is mainly found in animal-based sources such as fish oil and fatty fish.

Even the supplements that provide a good amount of omega-3 fatty acids are made from fish oil, making it even more likely for vegans to develop a deficiency of these nutrients.

However, it is possible to get adequate amounts of omega-3s including EPA and DHA by increasing the intake of plant-based sources of these nutrients such as chia seeds, flaxseeds, and walnuts (including young, green walnuts).

DHA is also present in microalgae, which can serve as a suitable dietary source for vegans.

4. Iron

Iron is one of the most crucial minerals that the body needs for the formation of hemoglobin. Hemoglobin has the ability to combine with gases such as oxygen and carbon dioxide and carry them through the bloodstream.

Iron, once converted to hemoglobin, can combine with oxygen that we breathe in to form oxyhemoglobin.

Oxyhemoglobin, in turn, is transported through the blood to all the organs of the body to carry out the process of respiration or energy production.

Similarly, carbon dioxide, which is a waste product released by the cells, gets attached to the hemoglobin forming carboxyhemoglobin to be carried back to the lungs so that it can be removed from the body during exhalation.

A deficiency of iron can hamper these processes leading to the reduced availability of oxygen to the tissues, and in severe cases, a build-up of harmful carbon dioxide in the body.

This marks the importance of ensuring your body is not deprived of iron.

However, iron in the form of heme is found only in animal-based foods such as meat, especially red meat. The heme form is absorbed in the body more efficiently than the non-heme form of iron, which is found more commonly in plant foods.

Also, heme iron can improve the absorption of non-heme iron. This means without adequate heme iron, non-heme iron may not be efficiently absorbed in the body.

The absorption of non-heme iron may get limited further due to anti-nutrients like phytic acid present in some plant foods.

This is what makes vegans more prone to develop iron deficiency anemia and related complications.

A well-planned vegan diet that comprises an adequate amount of non-heme iron can be a great way to avoid the deficiency of this nutrient.

Some plant-based sources of iron include:

  • Spinach
  • Beetroot
  • Apples
  • Beans
  • Lentils
  • Potato with skin
  • Nuts and seeds
  • Dark chocolate

5. Calcium

Calcium is another essential mineral that is crucial for maintaining optimum bone and teeth health. It plays a key role in nerve signaling, muscle function, and heart health.

Milk and other dairy products are the commonest sources of calcium. This is one of the reasons why most vegans do not get enough calcium.

The inadequate supply of calcium to the body can make the bones and teeth weaker. This can elevate the risk of osteoporosis that occurs due to the loss of bone mineral density making the bones weak and prone to fractures. The deficiency of calcium can also result in brittle teeth and poor nerve conduction.

This is why; vegans should ensure their diet comprises an adequate amount of calcium.

Some of the best plant sources of calcium include:

  • Turnip greens
  • Kale
  • Bok choy
  • Mustard greens
  • Watercress
  • Broccoli
  • Calcium-set tofu
  • Chickpeas
  • Fortified plant milk and juices

6. Zinc

Zinc is crucial for metabolism and immune function. It also helps in supporting the repair and healing mechanisms of the body at the cellular level.

An insufficient supply of zinc can lead to hair loss, recurring diarrhea, and delayed healing of wounds. In children, it can result in developmental problems.

Zinc is found in abundance in animal-based foods such as meat, poultry, and seafood.

A recent review has revealed that vegans are more likely to have a deficiency of zinc.

The inadequate supply of zinc can put them at risk of slower metabolism, weak immune function, and inefficient repair and healing of the damaged tissues.

There are very few plant foods that can provide an adequate amount of zinc. Moreover, the absorption of zinc from some plant foods tends to be limited due to the presence of a compound called phytate in them.

Hence, vegans are encouraged to increase their intake of foods containing zinc so that they are not deprived of this mineral. To maximize their intake, they can eat a variety of zinc-rich plant foods throughout the day.

Some of the best vegan sources of zinc include:

  • Wheat germ
  • Whole grains
  • Tofu
  • Nuts and seeds
  • Sprouted bread
  • Legumes

7. Iodine

Getting enough iodine is essential for maintaining healthy functions of the thyroid gland, which controls the body’s metabolism.

A deficiency of iodine can reduce the secretion of hormones in the thyroid due to which the risk of hypothyroidism can increase substantially.

Hypothyroidism can cause several disturbing symptoms, including low energy levels, dryness of the skin, tingling in the hands and feet, hair growth on the face in women, forgetfulness, weight gain, and depression.

Iodine deficiency during pregnancy and early infancy can also lead to an irreversible intellectual disability.

Iodine is more commonly present in animal-based foods such as beef liver, chicken, eggs, fish, shellfish such as cod, oysters, canned tuna, and shrimp, as well as dairy products like milk, cheese, and yogurt.

Vegans are at higher risk of iodine deficiency due to the lack of plant-based sources of this nutrient.

Vegans can use iodized salt for cooking to protect themselves against the risk of iodine deficiency and related complications like hypothyroidism.

They can also consume seaweed like nori, kelp, kombu, and wakame to ensure they are not deprived of this nutrient.


Begin aware of the vitamins, minerals, and other nutrients that are difficult to obtain through a vegan diet is essential for vegans to be able to make correct food choices that can help them maintain optimum physical and mental health.

A well-planned vegan diet can ensure your body receives an adequate supply of essential nutrients that can allow you to stay fit and healthy year after year.

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