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Vegan and vegetarian diets are both very healthy ways of eating.
They’ve been linked to multiple health benefits and a lower risk of excess weight, heart disease, and even some types of cancer.
However, a few nutrients are either difficult or impossible to get in adequate amounts from plant foods alone. That’s why it’s very important to be aware them and supplement your diet to maintain health or physical performance.
Here are 7 nutrients commonly lacking in vegetarian and vegan diets.
Also known as cobalamin, it’s a water-soluble nutrient involved in developing red blood cells and maintaining nerves and normal brain function.
Studies have shown that without supplements or enriched foods, vegetarians are at a high risk of vitamin B12 deficiency (
Lacto-ovo-vegetarians can get adequate amounts of this nutrient from dairy products and eggs, but this is much more challenging for vegans (
The symptoms and risks associated with vitamin B12 deficiency include:
- weakness, fatigue (
- impaired brain function (
- neurological disorders (
- psychiatric disorders (
- neurological disorders in babies of breastfeeding mothers (
- megaloblastic anemia (
- possible links to Alzheimer’s disease (
- possible links to heart disease (
To get sufficient amounts of vitamin B12, people following a vegan diet must take supplements or eat food that has been fortified with this nutrient.
- enriched yeast extracts
- soy products
- breakfast cereals
- meat substitutes
In addition, a few plant foods naturally contain trace amounts of bioactive vitamin B12, including:
- nori seaweed, a type of marine algae (
17, 18, 19, 20)
- tempeh, a fermented soy product (
- shiitake mushrooms
Nori seaweed is considered the most suitable source of biologically available vitamin B12 for vegans, though it doesn’t provide a sufficient amount on its own (
However, those are not considered to be sufficient sources of dietary vitamin B12 and do not provide the daily need.
Another plant food often claimed to contain vitamin B12 is spirulina.
However, spirulina offers only pseudovitamin B12, which is not biologically available (meaning it can’t be absorbed by the body). For this reason, it’s unsuitable as a source of this vitamin (
If you want to boost your vitamin B12 intake, you can buy vegan-friendly supplements locally or online.
Vitamin B12 is only found in animal and fortified foods, as well as in small amounts in certain types of seaweed. People following a vegan diet should supplement with a vegan vitamin B12 supplement.
Creatine is a molecule found in animal foods. Most of it is stored in your muscles but significant amounts are also concentrated in your brain.
It functions as an easily accessible energy reserve for muscle cells, giving them greater strength and endurance (
Creatine is not essential in your diet, since it can be produced by your liver. However, studies have shown that vegetarians tend to have lower amounts of creatine in their muscles (
One study placed people on a lacto-ovo-vegetarian diet for 26 days and found that doing so caused a significant decrease in their muscle creatine levels (
Because creatine is naturally found in animal tissue, vegetarians and vegans can get it only from supplements.
For vegetarians, creatine supplements may have significant benefits, including:
Some of these effects are stronger in people on a vegetarian diet than in meat eaters. For instance, vegetarians taking creatine supplements may experience significant improvements in brain function while people who eat meat see no difference (
This may be attributed to the meat eaters already having higher levels of creatine in their muscles as a result of their diet.
You can purchase vegan-friendly creatine supplements locally or online.
Creatine is a bioactive compound that’s lacking in plant-based diets. It plays an important role in brain and muscle function.
Carnosine is only found in animal-based foods. However, it’s considered nonessential, since your body can form it from the amino acids histidine and beta-alanine.
Dietary sources of beta-alanine may contribute significantly to muscle levels of carnosine, but the main dietary sources — meat, poultry, and fish — are nonvegetarian.
There are multiple vegan beta-alanine supplements available online.
Carnosine is a nutrient found only in animal-derived foods. It’s important for muscle function. Beta-alanine supplements increase the levels of carnosine in muscles.
Vitamin D is an essential nutrient with many important functions. Also called the sunshine vitamin, it doesn’t have to come from your diet.
Your skin can produce vitamin D when it’s exposed to sunlight. However, if your sunlight exposure is limited or you live far from the equator, you must get it from food or supplements.
There are two types of dietary vitamin D:
- ergocalciferol (D2), found in plants
- cholecalciferol (D3), found in animal-based foods
The best sources of vitamin D3 are fatty fish and egg yolks. Other sources include supplements, cod liver oil, or enriched foods like milk or cereals (
Since the main dietary sources of vitamin D3 are not plant-based, vegetarians and vegans may be at a higher risk of deficiency, especially during the winter in countries north or south of the equator.
Deficiency in vitamin D is linked to an increased risk of various adverse conditions, including:
- osteoporosis, with an increased risk of fractures in older adults (
- cancer (
- heart disease (
- multiple sclerosis (
- depression (
- impaired brain function (
- muscle wasting and reduced strength, especially in older adults (
53, 54, 55, 56)
Cholecalciferol (D3) is a type of vitamin D found in animal-sourced foods, especially fatty fish, and it’s more effective at raising blood levels of vitamin D than the plant form of vitamin D (D2). Vegan vitamin D3 supplements can be purchased online.
Deficiency in DHA can have adverse effects on mental health and brain function, especially in children (
It’s mainly found in fatty fish, fish oil, and certain types of microalgae.
However, the conversion of ALA to DHA is very inefficient and may not increase blood levels of DHA sufficiently (
These supplements are available in specialty stores and online.
Docosahexaenoic acid (DHA) is an essential omega-3 fatty acid found in fatty fish and fish oil. It’s also present in microalgae, which are a suitable dietary source for vegetarians and vegans.
Heme iron also improves your absorption of non-heme iron from plant foods. This phenomenon is not entirely understood but is called the meat factor.
Non-heme iron is poorly absorbed. Its absorption can be limited further by anti-nutrients also present in plant foods, such as phytic acid.
Unlike non-heme iron, the absorption of heme iron is not affected by the presence of antinutrients.
However, iron deficiency is easy to avoid on a well-planned vegan diet that contains plenty of non-heme iron.
Meat, especially red meat, contains a type of iron called heme iron, which is much better absorbed than non-heme iron from plant foods.
Taurine is found only in animal-sourced foods, such as fish, seafood, meat, poultry, and dairy products (
Taurine isn’t considered essential in the diet, since your body produces small amounts. Still, dietary taurine may play a role in maintaining your body’s taurine levels.
Synthetic taurine supplements are widely available and suitable for vegetarians and vegans.
Taurine is a sulfur compound that has several functions in your body. It’s found naturally in only animal-based foods but is also available in synthetic supplement form.
Well-planned vegetarian and vegan diets are very healthy. Unfortunately, a few nutrients are impossible or difficult to get from commonly consumed plant foods.
If you plan to eliminate animal-sourced foods from your diet, make sure to keep those nutrients in mind, and take dietary supplements to make sure that you’re getting everything your body needs.