Vegan Diet - Benefits and Deficiencies

Posted by Florian Hosner on

Plant-based nutrition brings many advantages:

  • Lower cholesterol levels
  • Less risk for cardiovascular disease and diabetes
  • A higher amount of fiber and generally fewer calories per meal

If you want to learn more about these advantages, you can read our article Why we should eat more plants. There is a range of benefits and our general opinion is that we should eat more plants and use these benefits for our diet and health.

However, many people also have concerns about plant-based nutrition. They think that a vegetarian and moreover a vegan diet is connected to inefficiencies and is even unhealthy. Where do I get my protein from? What about minerals like Calcium? Vegan = Deficiencies! Those are some common concerns that you hear all around these days.

Well, is this the case? As I always like to say, let’s go into detail and have a look at the chemistry first … and then we can work out our opinion, based on facts and data.

Does it make sense to go vegan?

The crucial question first. Should you go vegan? The answer to such a question is never just a Yes or a No. Why do you want to go vegan? Is it because you respect animals and you do not want to kill them? Is it because you want to save the environment and produce a lower carbon footprint? Is it because you want to live healthier? Is it because you want to lose weight? There can be several reasons for this decision and everybody has his own opinion and motivation.

I can give you my personal opinion as a chemist and as a person that loves animals. However, I want to state that I respect other opinions. I am not one of these militant people that only can see their own dump heap and are not able to look beyond. This is one of my favorite quotes that my mother, (a retired teacher) used in school when she was discussing with young farmer children from the Austrian countryside. If you go through YouTube channels and listen to the discussions on this topic you feel like on a battleground sometimes.

Chill people! It is everybody’s private decision and we need to respect that.

So, my personal opinion is, that we should eat more plants because it is very healthy. I do not recommend going completely vegan though, because I think then you need to be very careful with your choices of food to get all nutrients in the right concentrations. Is it possible to live healthily as a pure vegan? Yes, you can live very healthy being a vegan. Is it necessary to be a vegan if you want to live healthily? No. I think it makes sense to have a more balanced approach. Eat more plants, cut the carbs a little and you will be fine. I eat dairy products and eggs, and I love to eat fish sometimes. I try to cut red meat as often as possible.

This is my opinion from a nutritional or health perspective.

If you love animals (what I do) and you do not want to eat any meat because you think it is just not right, I understand your position and I highly respect it. Go for it! You can live a healthy vegan lifestyle if you make the right food choices. Just be careful and aware of what nutrients you need and where you can get them from. I will teach you some important things in the next chapters.

This is my opinion from a humanitarian perspective.

If you do not want to eat meat because you want to save the environment, I understand your position and I highly respect it. 15% of all greenhouse gas derives from livestock farming. One fattening pig consumes about 1 million liters of drinking water. These are very good arguments for going vegan.

This is my opinion from an environmental perspective.

Summarized I share the concerns of many vegan people regarding animal and environmental protection. My approach is to cut the consumption of animal products to a certain amount but I do not completely go vegan myself.

Ok, now all you militant vegans and meat-eaters, you can make your jokes about me, but please don’t kill me, because I am about to give you some valuable information on a plant-based diet, deficiencies, and supplementing in the next chapters!

What are the critical nutrients?

It is a fact that a vegan diet has a different nutritional spectrum compared to a standard- or so called “Western Pattern-Diet”. I will not go through all nutrients, because this is simply impossible, but I will give you the most important points that you need to consider. The US Institute of Medicines publishes “Dietary Reference Intakes” (DRI) for the most important macro and micronutrients that are a good guideline for how much you should consume of them. We will use these DRI values as a guideline for your required quantity for each nutrient. If it is hard to achieve the daily DRI with plants only, then we need to consider supplementing if we want to avoid deficiencies on a vegan diet. 


In contrast to popular beliefs, it is quite easy to get enough protein when you are on a vegan diet. Many plants are rich in protein. The DRI for protein is 0.8 g per kg of body weight (or 0.36 g per pound). That means an average man should consume 56g protein daily and an average woman should consume 46g protein daily. This is possible, eating only plants. I will give you a list of plants that are high in protein. If you use them for your diet you will have no problems with meeting your DRI. (All figures are calculated for 100g of the food)

Hemp Seeds 33.0 g
Peanuts 26.0 g
Almonds 21.0 g
Lentils 17.9 g
Chia Seeds 17.0 g
Soy 16.6 g
Beans 15.0 g

You can easily meet your protein DRI if you mix enough soy, seeds, and nuts into your diet. It is absolutly not true that all vegans have a protein deficiency per se … Myth busted!


Iron only comes with animal products … Not true! Another myth. However, iron from plants has another bioavailability compared to animal products. Our bodies cannot use it as easily as iron from animal products. The Institute of Medicine recommends vegans a DRI of:

for men

14 mg

for menstruating women

32 mg

for pregnant women

39 mg

These values are possible with a vegan diet. You just need to make sure to eat the right plants. Here is a list of foods that include high amounts of iron: (All figures are calculated for 100g of the food)

Pumpkin Seeds

15.0 mg

Sesame Seeds

14.5 mg


7.5 mg


7.5 mg

Cahew Nuts

6.7 mg

Vitmin D & Calcium:

Vitamin D plays a big role in the adsorption and bioavailability of Calcium, Magnesium, and Phosphate. Without vitamin D these minerals cannot be utilized well by our bodies. The DRI for vitamin D is 600 UI, which means 15µm per day. We can produce vitamin D in our skin when we get enough sunlight. In the summertime, our whole vitamin D consumption can be met by ca. 30 minutes of sun exposure. In southern countries below latitude 37°, this is possible the whole year. In countries like the US or UK, this is only possible in the summer time.

The other possible source of vitamin D is food. There are only certain foods that contain higher amounts of vitamin D: (All figures are calculated for 100g of the food)

Wild Mushrooms

5-30 µg



So if you are a vegan we recommend that you go out and get enough sun in summer. In winter you might consider supplementing if you do not want to eat loads of tofu and mushrooms.

Calcium is the team player of vitamin D. Typically, Calcium is found in dairy products and if you consume enough milk and cheese you will not get issues with Calcium deficiency. Calcium is very important for the health of our bones and muscles. If we do not get enough we get issues with our bone density and our muscles don’t work properly! Calcium is activated by vitamin D and our body is better able to absorb it with vitamin D. So if you do not get enough vitamin D you can also get issues with Calcium. The DRI for Calcium is 1.000 mg per day. There are some plants with a higher amount of Calcium: (All figures are calculated for 100g of the food)

Chia Seeds

631 mg


216 mg


197 mg

White Beans

173 mg

Wakame Sea Weed

150 mg

You see that it is also possible to get enough Calcium with plant-based diet, but it is not so easy. We recommend eating fortified foods or supplement both Calcium and vitamin D.

Vitamin B12:

Vitamin B12 - Quite complex & quite important
Vitamin B12: Quite complex & quite important

Here comes a tough one. Vitamin B12 is a very important molecule that we need for a good function of our nervous system and the production of our red blood cells. It is only produced in certain bacteria. Animals consume these bacteria with their nutrition and Vitamin B12 gets enriched in animal tissue. If you only eat plants it is hard to get your DRI of 2.4 µg.

There are some plant sources like tempeh algae (0.1 µg/100g), but basically, it is not possible to meet your DRI without supplementing. If you are on a vegan diet you should track your vitamin B12 level and you should consider supplementing! Consult your professional medic and get yourself a good supplement. 

Omega-3 fatty acids:

The next challenge. Omega-3 fatty acids are important for your brain’s health, skin’s health and can have positive effects on our cardiovascular system. If you want to learn more about fatty acids you can check out our blog post: Good Fat & Weight Loss. Several studies indicate that Omega 3s can reduce the risk of inflammations and the risk of certain diseases of our brain and cardiovascular system, although this last topic is still under intense research. 

There are 3 different Omega-3-fatty acids:

  • α-Linolenic acid (ALA)

  • Eicosapentaenoic acid (EPA)

  • Docosahexaenoic acid (DHA)

EPA and DHA can be produced out of ALA by our body, so basically ALA is the only essential Omega-3-fatty acid. 

There is no DRI published for Omega 3s. However, the National Institute of Health recommends a daily intake of 1.1g ALA per day for females and 1.6g ALA per day for males. The best sources for ALA are:

Flax seeds

22 g

Chia seeds

17 g


Now if you look at these figures you might think: “Easy. That’s not a problem at all”. However, several studies have shown that the production of EPA and DHA is very limited for vegans. The main reason is a misbalance between Omega-3s and Omega-6s on a vegan diet. So, basically, vegans end up with too little EPA and SHA and no good natural source to get them. (e.g. fish or fish oil)

We recommend supplementing Omega-3s to get enough EPA and DHA for your body if you are a vegan. Consult your professional medic and get yourself a good supplement. 

Versatility vs supplementing

Deficiencies always derive from restrictions. If you don’t eat certain foods and have a low versatility in your choice of meals, you will finally end up with deficiencies. It does not matter if you only eat meat or you only eat plants. The problem stays the same. Restriction leads to deficiencies. Period.

So, if you decide to cut certain types of food you will need to be more careful with your planning. It will get harder and harder to get all nutrients from your smaller selection of foods.

If you are on a vegan diet, this is also true of course. It is possible to get enough protein, iron, calcium, and vitamin D if you make the right food choices and you have a very good plan.

You should consistently track the critical nutrients and consult your professional medic regularly if you are on such a restricted diet. However, you can live very healthy if you make the right choices and have good versatility in your list of foods. However, you will have a very hard time with omega 3s and vitamin B12. It is nearly impossible to get enough of them if you do not want to eat algae and flax seeds the whole day. Supplementing is the only way to get enough of these important nutrients if you only eat plants.

If you take supplements and make sure that you get enough of all nutrients a vegan diet can be a very healthy lifestyle. It is a lot of work of course and you constantly need to make conscious decisions about your meals and regularly check your blood, but on the other hand, you will have a much lower risk for certain diseases like diabetes, cardiovascular disease, stroke, obesity, etc. I think this is a fair deal …

The bottom line:

If you want to live healthier eat more plants! This is a tip I like to give people that ask me what they should change. We always tend to eat too much meat, too many carbs, and too little plant-based nutrition.

If you want to make a change because of your health or bodyweight, I do not recommend going vegan. It is not necessary. Make a compromise and for example, don’t eat meat on 5 days of the week. Increase the amount of plant-based nutrition instead. This will give you a lot of benefits without restricting your diet too much.

If you want to be vegan because of humanitarian or environmental motivations, I totally understand your choice and I highly respect it. You can live a very healthy lifestyle with a vegan diet. Just make sure that you track all critical nutrients that we have shown you in this article and we highly recommend supplementing vitamin B12, Omega-3-fatty acids, vitamin D, and Calcium. You should also continuously consult a professional medic and check your blood to make sure you do not develop any deficiencies. But don’t get me wrong! If you do it right you will live a healthier life than 90% of our western population. And this is great! 

And everybody, keep in mind: Versatility prevents deficiencies! Make sure that you have a broad choice of foods in your diet and vary your dishes to get all nutrients that you need. Your body will say “Thank You!”



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