Recently, plant-based vegetarian eating has increased in popularity. According to a survey published in 2016, 10% of the population opted to exclude animal food from their diet, and for good reasons.18 A balanced vegetarian or vegan diet can provide many health benefits. These diets may confer protection against cardiovascular disease, cardiometabolic risks, and may be associated with improved weight control, better blood sugar control, a decreased risk of heart disease, and a lower risk of certain types of cancer.13-16

On the other hand, restrictive dietary patterns, such as vegetarian diets, make it more difficult to obtain adequate amounts of all essential nutrients. By eliminating animal foods, a vegetarian diet could be unbalanced – lacking in nutrients that are either poorly represented, or with a low bioavailability in vegetal foodstuffs.

From a nutrient intake perspective, vegetarian diets are usually rich in carbohydrates, n-6 polyunsaturated fatty acids, fiber, carotenoids, folic acid, Vitamin C, Vitamin E, and magnesium, but may be relatively low in proteins, long-chain omega-3 polyunsaturated fatty acids (eicosapentaenoic (EPA) and docosahexaenoic acids (DHA), Vitamin A (retinol), Vitamin B12, Vitamin D3 (chlolecalciferol), zinc, iron, and calcium.20 Let’s look at some of the most common mistakes people make on a vegetarian diet, and how to avoid them.



Food (meat, milk, eggs, fish, and shellfish) derived from animals are considered the major dietary sources of Vitamin B12, thus vegetarians are at risk of developing deficiencies of vitamin B-12 (cobalamin).17, 18, 19 In fact, the frequencies of deficiency among vegetarians were estimated at 62%, 25%–86%, 21%–41%, and 11%–90% in pregnant women, children, adolescents, and elderly subjects respectively, according to a comprehensive review of 18 reports about the Vitamin B12 status of vegetarians.20

To prevent Vitamin B12 deficiency in such a high-risk population, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12, and consider taking supplements if their needs aren’t met through diet alone.

If you follow a lacto-ovo vegetarian diet, and you’re allowed to consume milk and milk products and/or eggs, these can help you at least partly to meet your B12 needs. Please keep in mind, however, that vitamin B12 content is not too high in whole eggs, and most of it is located in the egg yolk. Moreover, the average bioavailability of Vitamin B12 from cooked eggs is 3.7%–9.2%. 20,21 The vitamin B12 content of milk is also low with cottage cheese, hard cheese, and blue cheese as the most ideal sources in this regard.

Besides animal products, fortified foods, certain types of edible mushrooms, edible algae, fermented beans, and fermented vegetables may provide higher amount of vitamin B12.

Dried purple laver (nori) has been identified as one of the richest non-animal source of B12, while chlorella may also provide biologically active Vitamin B12.20

The most commonly eaten mushrooms in Europe, such as porcini and pleurotus, do not contain relevant amounts of vitamin B12. Selected types of oyster mushrooms, however, as well as horn of plenty (Craterellus cornucopioides), Chanterelle (Cantharellus cibarius), Shiitake and Lion’s mane mushrooms may offer considerable amounts of B12.

And last but not least, fermented vegetable foods, such as sauerkraut, natto and tempeh, can also provide significant amounts of B12.18, 20



Dairy products provide a wide range of nutrients that may be difficult to obtain with limited or no dairy consumption. In balanced omnivore diets, dairy products contribute around 52–75 % of the reference intake of calcium. 1-9 In fact, using data from the National Health and Nutrition Examination Survey (NHANES), researchers concluded that adequate calcium intake cannot be met with dairy-free diets in adolescents, while meeting other nutrient recommendations.11

If you are unable, or unwilling to consume dairy products, you should be aware of which foods provide the range of nutrients generally obtained from dairy, especially calcium. Calcium choices for those who do not consume dairy products include green leafy vegetables such as collard and turnip greens, kale, bok choy, legumes including soybeans and other soy products (tofu made with calcium, soy yogurt, tempeh), some other beans, and calcium-fortified foods (juices, cereals, breads, rice milk, almond milk or other non-dairy “milks”).

Keep in mind that non-dairy sources of calcium, including green leafy vegetables and legumes, may contain compounds such as oxalic acid and phytic acid that inhibit calcium absorption. For example, cooked spinach contains about 115 mg of calcium per serving, but only 5% of this is absorbed. Spinach contains a high level of oxalates which bind calcium and form insoluble salt compounds.12 Foods with high levels of oxalic acid include spinach, collard greens, sweet potatoes, rhubarb, and beans. Fiber-containing whole-grain products such as wheat bran, beans, seeds, nuts, and soy isolates are high in phytic acid.



Proteins are nitrogen-containing compounds that are vital for life,. In fact, the human body is comprised of 16-19% of protein. The protein found in foods is used by every part of our body to develop and function properly. Even the name refers to their importance, because the word “protein” is derived from the Greek word “protos”, meaning “primary” or “first”. Thus, adequate protein intake is vitally important to maintain overall health, and maximum physical, and mental performance.

Although a variety of plants provide significant protein, plant-based protein sources are often incomplete, missing important essential amino acids, and typically have lower biological value, and digestibility compared to animal products,. This may need to be considered when designing a vegan diet.23 But, according to the American Dietetic Association: “plant protein can meet protein requirements when a variety of plant foods is consumed and energy needs are met.”22

So try to choose and consume a wide variety of plant-based sources to cover your protein bases. In addition, it has been suggested that vegetarians might need to consume a little bit more protein than meat eaters to compensate for the poorer digestibility of plant-based sources. 23, 24

Nuts, seeds, and legumes including all types of beans, lentils, chickpeas, split peas, and soy products offer rich sources of proteins. But don’t forget that these sources are usually high in carbs and/or fat, so you have to take into account. Supplemental protein might be of interest to vegan athletes, and dieters. So if you would like to increase your protein intake without extra calories, a high-quality plant-based protein supplement may be a good option.

In a study published in Nutrition Journal, participants were randomly supplemented with 48 grams of rice or whey protein isolate on training days. Both whey and rice protein isolate taken after resistance exercise improved indices of body composition and exercise performance. There was, however, no differences between the two groups.25



With high intake of whole-grains, legumes, nuts, seeds, fortified foods, and green vegetables both vegetarians and vegans may consume similar amounts of iron as omnivores. But the bioavailability of plant-based iron is found to be far lower than the bioavailability of hem iron found in animal products. In addition, the main sources of iron in a plant-based diet usually contain dietary inhibitors such as the polyphenols, tannin and phytates, which further decrease the amount of iron absorbed from our foods.

Although, it has been suggested that the body can regulate iron absorption based upon our actual iron status,23, 27 and thus low iron status can lead to an increased intestinal absorption, if you’re a vegetarian, make sure to consume a wide range of good plant-based sources of iron. These include lentils, beans, fortified cereals, nuts, seeds, and leafy greens. In this regard, the Institute of Medicine (IOM) suggests that iron requirements for vegetarians are 1.8 times greater than omnivores.23, 28

In addition, try to combine these iron-rich foods with foods high in vitamin C, because it can improve iron absorption.26 Check your iron status regularly, and supplement your diet as needed.


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