Common nutritional imbalances among vegans and vegetarians

According to a 2020 Green Queen survey, 23% of Hong Kong people transitioning to a plant-based diet cite health reasons as their motivation. Despite this, nutritional imbalances are common among the vegan community, and a German survey suggests that up to 54% of vegans don’t take supplements. In stark contrast, 98% of healthcare professionals who are vegan do take supplements.  

The German Nutrition Society (DGE) recommends that vegans conduct regular lab tests to ensure they don’t have nutritional imbalances, yet a ‘substantial proportion’ of vegans report irregular health checks.

In Green Queen’s survey of 200 participants, 54% described themselves as vegan and 18% as vegetarians. The same year, the PwC released research which stated that 27% of Hong Kongers were considering becoming vegan or vegetarian the following year.

It’s clear that vegan diets are on the rise, and with 44% citing animal rights, and 24% citing the environment as their reason for changing their diet, ethics are at the centre of their decision.

Yet, those going plant-based need to be careful that they don’t compromise their health while directing their energy towards the big issues. Healthy, well-planned and appropriately supplemented vegetarian and vegan diets can improve heart health, reduce cholesterol, blood pressure and reduce oxidative stress, but poorly planned plant-based diets carry many of the health risks that meaty diets do and can cause dysbiosis, high blood sugar and high blood pressure.

Careful planning of your diet, and when appropriate, supplementing, helps ensure that you stay healthy when you make the switch to becoming plant-based.

Vitamin B12

Vitamin B12 is almost exclusively found in animal products. Research shows that 52% of vegans have inadequate levels of vitamin B12. Between 50% to 70% vegetarians are cited to have low levels.

Signs of B12 imbalance include fatigue, feeling weak or faint, memory problems, stress or low mood.

The recommended daily intake of B12 is 2.4 micrograms per day. Vegetarians can turn to dairy products and eggs to support B12 levels. Nutritional yeast is a possible dietary option for vegans, but different brands provide different amounts of B12 per serving, so check the label when you buy. That said, nutritional yeast can be an acquired taste.

Studies show that vegans who supplement show higher levels of B12 and scientists recommend supplements as a simple way to avoid imbalances.
B-Supreme by Designs for Health features a range of active B vitamins in their optimal form for easy absorption. A broad range B vitamin supplement is often better than a specific B12 formula, as vegetarians and vegans are also at higher risk for B1, B2, B3 and B6 imbalances.

Iron

Due to menstruation, women and girls on plant-based diets are more likely to have insufficient levels of iron. The results from research vary, but a 2016 review found that female vegetarians with inadequate iron levels ranged from 12-79%. Among boys and men, the figure ranged between 1.7% to 29%. Women are widely underdiagnosed for low iron, and scientists recommend that organisations like WHO should raise their lower threshold for iron levels, describing it as inappropriately low. If a higher, more appropriate threshold was put in place, many more vegans and vegetarians would be labelled as having insufficient iron levels.

Symptoms of iron imbalance include fatigue, weakness and pale skin.

There are many plant-based foods that are rich in iron, like leafy greens (kale, bok choy, spinach, collards, swiss chard), broccoli, avocado, potatoes (skin on), oats, tofu, quinoa, kidney beans, lentils, dark chocolate, and chickpeas. Though eggs are sometimes cited as a good vegetarian source of haem iron, the yolk contains a protein called phosvitin which inhibits iron absorption.

Unfortunately, the absorption of plant-based sources of iron are inhibited by phytates, oxalic acid, polyphenols and tannins. These compounds are found in many foods, ironically, often those that are high in iron, rendering them an unhelpful source of iron. Spinach and chard are high in oxalic acid. Tofu and tempeh are high in phytates.

One way to increase the bioavailability of iron-rich food is adding a source of vitamin C to your meal. Adding strawberries or kiwi to your oats, or broccoli or red pepper to a tofu-based dish can increase the bioavailability of iron.

And bad news if you’re fond of tea, coffee or a glass of red wine in the evening, these drinks are all high in polyphenols and tannins which inhibit iron absorption.
Ferrochel Iron Chelate by Designs for Health is a premium iron chelate which replenishes iron levels effectively. 

Zinc

Plant-based sources of zinc include tofu, wholegrains and legumes like chickpeas, lentils and beans.

Similar to iron, these sources of zinc have a lower bioavailability, as they contain phytates which inhibit zinc absorption. A meta analysis of vegetarians found that their zinc levels were significantly lower than meat eaters, and another study cites that vegetarians fall 33.3% below the reference range, while vegans drop 42.5% below acceptable levels. Some studies suggest that women are more at risk for low levels. 

Soaking your legumes can help boost bioavailability by preventing the phytates from bonding to zinc and inhibiting absorption, however healthcare professionals recommend supplementation to avoid low levels.

For vegans, we recommend Zinc Citrate by Vital Nutrients which provides a healthy daily dose to support those on plant-based diets. Zinc Plus by Klaire Labs (also known as SFI Health) provides a vegetarian dose, with additional vitamin C, B6 and copper to support better zinc absorption.

Calcium

A systematic review of vegan diets shows that 76% of vegans eat less than the recommended daily amount of calcium. Calcium imbalances are widespread across the world, and are especially prevalent in those who don’t consume dairy products – so if you switch cow’s milk for oat milk, you should watch your calcium intake.

Muscle cramps, fatigue and nails prone to breakage are symptoms of calcium imbalance.

Even if vegans are eating the recommended intake of calcium, plant-based sources aren’t bioavailable, and like iron, absorption is inhibited by oxalate and phytates.

Research shows that the best plant-based calcium sources are kale, finger millet and fortified white bread. Kale provides 5 times the amount of calcium per serving than one serving of skimmed milk.

You can also opt for a supplement – but make sure it doesn’t feature calcium solo. Alone, calcium supplements can cause cardiovascular issues. Blended with magnesium, it offers protective benefits for your heart. Our naturopaths like Cal / Mag 2:1 by Designs for Health, delivered in the optimal ratio of calcium and magnesium.

Vitamin A

Remember your Mum telling you to eat your carrots so you could see in the dark?

Plants like carrots, sweet potatoes and mangoes are rich in beta-carotene, a precursor for vitamin A, which supports your eyesight, immunity, organ health, teeth and more.

What your mum didn’t tell you was that 45% of the population have genes which mean they have low responsivity to beta carotene. This means it can be tricky for vegans to obtain enough vitamin A from plant-based sources without supplementing. Imbalances can manifest as eye and skin problems.

Vegetarians can turn to eggs, milk, cheese and yogurt to obtain vitamin A directly. Vegans may want to support potential low-responsiveness to beta-carotene with an additional daily dose from a multivitamin, like Opti-Vita Complex by Natroceutics. For vegetarians, we recommend Twice Daily Multi by Designs for Health.

Adding fat to your meal can also help boost the absorption of vitamin A, which is fat-soluble. 

Omega 3s

The two omega 3s you need for brain function are EPA and DHA, which are generally found in fatty fish.

Common plant-based options include flaxseeds, chia seeds, hemp seeds and walnuts, which are sources of ALA. Your body converts ALA into EPA and DHA, but the process is inefficient. Only 5-10% is converted to EPA and 2-5% converted to DHA.

Eggs provide a source of DHA for vegetarians, but limited EPA.

The best source of plant-based omega 3 is algae, which is the original source of EPA and DHA. Fatty fish like salmon and sardines are a rich source of omega 3 because their diet is predominantly made up of algae.

Ultra Pure Vegan Omega SPM by Vital Nutrients goes straight to the source. Rich in vegan EPA and DHA, it’s the plant-based solution for getting your omega 3s. 

Vitamin D

Many of the bioavailable sources of vitamin D come from animals – and a systematic review on the nutritional profile of vegans and vegetarians revealed that those with plant-based diets are at higher risk of low vitamin D levels.

Results from studies vary, but vitamin D insufficiency among meat eaters ranged from 0 to 6%. Among vegetarians it ranged from 0 and 33%, and among vegans 3 and 67%.

You can get vitamin D from enough sun exposure, but in winter months, or if you regularly wear sun block, you might struggle to achieve adequate levels.

Opti-Vita Complex by Natroceutics features a vegan form of vitamin D3. Vegetarians can opt for Twice Daily Multi by Designs for Health.

Need some extra help navigating a plant-based diet?

If you are experiencing symptoms like fatigue, weakness, skin problems or digestive issues like bloating, abdominal pain or gas, it’s important to get checked out.
Our naturopaths conduct a thorough assessment of your health and when needed, refer you for testing to confirm nutritional imbalances.

You might have increased the number of FODMAP foods you’re exposed to (like onions, mushrooms and cauliflower) which can trigger sensitivity in your gut. Sometimes unknown allergies or sensitivities to foods can cause digestive issues. Our tests confirm the root cause of gut sensitivity, from leaky gut, to allergies or intolerances.

Our naturopaths and nutritional therapists can help you (and your family) plan for a vegetarian or vegan diet. They can help guide you if you’re unsure about which proteins you need to incorporate, or how to maintain a healthy diet whilst pursuing vegetarianism or veganism. 

References
Green Queen, 44% of Hong Kong people who are changing their diets are doing it for animals, survey data shows, 2021.
A Niklewicz et al, A systematic review and meta-analysis of functional vitamin B12 status among adult vegans, 2024.
S Fernandes et al, Exploring vitamin B12 supplementation in the vegan population: a scoping review of the evidence, 2024.
T Wang et al, Vegetarian and vegan diets: benefits and drawbacks, 2023.
The vegan society, Worldwide growth of veganism, 2025.
N Vudhivai et al, Vitamin B1, B2 and B6 status of vegetarians, 1991.
V Weinborn et al, The effect of plant proteins derived from cereals and legumes on heme iron absorption, 2015.
T Ems et al, Biochemistry, Iron absorption, 2023.
R Pawlak, Iron status of vegetarian adults: a review of literature, 2016.
B C Davis, Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications, 2003.
D Rafaila Bakaloudi, Intake and adequacy of the vegan diet. A systematic review of the evidence, 2021.
M Muleya, A comparison of the bioaccessible calcium supplies of various plant-based products relative to bovine milk, 2023.
G Lietz et al, Single nucleotide polymorphisms upstream from the β-carotene 15, 15’-monoxygenase gene influence provitamin A conversion efficiency in female volunteers, 2012.
M Jeitler et al, Knowledge, attitudes and application of critical nutrient supplementation in vegan diets among healthcare professionals – survey results from a medical congress on plant-based nutrition, 2022. 
M Foster et al, Effect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans, 2013.
L Klein et al, Selenium, zinc and copper status of vegetarians and vegans in comparison to omnivores in the nutritional evaluation (NuEva) study, 2023.