There’s an ongoing debate raging over whether it’s possible to get all your nutritional needs met on a purely vegan diet. Some argue that it’s possible to ingest all the nutrients your body requires, while others argue that you need to supplement certain areas where a vegan diet may fall a bit short.

I’m not too excited by online arguments anymore, so I choose to follow the evidence.

While science indicates it is possible in theory to meet your nutritional needs with a vegan diet, science also clearly shows there are certain areas of nutrition where most vegans probably need a bit of extra help, to ensure their needs are met.

I’ve listed the seven most common nutritional problem areas here, along with a short explanation of why they are important, where you can get them, and how you could supplement. Depending on your specific diet and lifestyle some of these may not be problem areas for you. If in doubt, have a chat with your doctor who would be able to arrange a blood test to determine whether you are at risk in any of the nutrients listed here.


Vitamin B12

B12 plays a number of vitally important roles in your body, including the formation of red blood cells (which carry oxygen through your body), protein metabolism, as well as keeping your nervous system in tip top shape.

A lack of vitamin B12 could lead to serious health issues, including anemia, infertility, and a range of neurological issues. It really is vitally important to ensure you’re getting enough B12, especially as a vegan, because the most common natural sources of B12 are animal-based1.

There are lots of tall tales and unconfirmed reports of where vegans can or could get vitamin B12. Unwashed vegetables, for example, is a popular source I see mentioned quite often.

Fact is, the only scientifically verified and reliable source of vitamin B12 for a vegan is through fortified foods or vitamin supplements2. Nutritional yeast and breakfast cereals are popular and affordable ways to get your B12 numbers up.

On the topic of nutritional yeast: please make sure you buy the right brand. Nutritional yeast does not contain B12 by default – only when fortified – so read the label before you proceed to check out. Vitamin B12 is light sensitive, so try to avoid buying it in clear packaging.

One last thing: our body’s ability to absorb vitamin B12 naturally declines with age, and the Institute of Medicine recommends that everyone over the age of 51 supplement their B12 whether they are vegan or not3.


EPA/DHA (Long chain Omega-3 Fatty Acids)

Omega-3 fatty acids play an important part in keeping our minds and eyes healthy, and also appear to help combat internal inflammation and certain types of cancer4.

There are different types of Omega-3’s (ALA, EPA, and DHA) and vegans typically have up to 50% less EPA and DHA in their bodies than omnivores5.

ALA is commonly found in a number of plant-based sources, like flax, chia, walnuts, and more. Your body then uses some of the ALA to manufacture EPA and DHA, though this conversion rate is quite low and usually means vegans end up deficient unless they’re making a concerted effort to get their numbers up.

The simplest approach to ensuring you are getting an adequate supply of Omega-3 fatty acids is to supplement daily with an algae oil (not recommended for kids – the taste takes some getting used to), or linseed/flaxseed oil supplement.



You probably already know how vitally important iron is for your helath. It carries oxygen through your veins, is used to make DNA and red blood cells, as well as a wide range of other metabolic processes6.

A lack of iron can lead to anaemia, fatigue, and reduced immune function.

While iron is found in plentiful plant-based supply it is quite common for vegans to be iron-deficient. To ensure your numbers are up, make sure you eat enough iron-rich foods: cruciferous vegetables, beans, peas, nuts, and seeds are all good ways to bump your iron levels up.

One thing to be aware of is that plant-based iron (non-heme iron) does not absorb as efficiently into your body as heme iron, which can only be found in animal sources.

Due to this difference in absorption rates (between plant-based and animal-based iron into your body) you should aim for a higher RDA than normally recommended, if you are vegan7.

Vitamin C also helps with iron absorption, so if you’re concerned with your iron levels ensure you get an adequate supply of vitamin C along with your iron.


Vitamin D

Vitamin D helps your body absorb calcium and phosphorus, and is involved in a range of other biological processes including mood, memory, and immune function8.

While vitamin D is also created by your body when exposed to sunlight you should not rely on this approach to getting enough, as you would need at least 20 minutes every day in strong sunlight with most of your skin exposed and with no sunscreen. Not a great idea, given the danger of skin cancer.

There are many fortified sources of vitamin D, like plant milk or cereals. The only good natural source of plant-based vitamin D are wild mushrooms, or mushrooms grown while exposed to ultraviolet light (like sunlight). Most commercial mushrooms are grown in the dark, so a risky way to get this important micronutrient.

The most accurate way to know whether you’re getting enough vitamin D into your body is by taking a simple blood test. If the numbers are low, or even if you are keen to keep your vitamin D numbers up I would recommend supplementing with a vegan vitamin D3 supplement.



Calcium is a mineral that helps you build strong bones and teeth, and plays a role in a number of biological processes.

Calcium can be found in wide range of plant-based sources, like dark leafy greens, cruciferous vegetables, beans, lentils, and more.

That said, science does seem to confirm that most vegans aren’t getting enough calcium9. While there is a debate around whether vegans need as much calcium (as omnivores), the fact remains that vegans tend to break bones more often10, suggesting some help on this front won’t go amiss.

Aim for the daily RDA of 1,000mg (or 1,200mg if over 50), through the help of supplements or fortified foods if necessary.



Zinc plays an important role in the healing process, immune function, and metabolism.

This important mineral can be found in a wide range of plant-based food, including whole grains, legumes, and tofu.

One thing to be aware of is that absorption of zinc into your body, as a vegan, can be hindered by the high phytate content of other foods you’re consuming, which is why you should aim for a daily intake 1.5x higher than the RDA11.

To counteract the negative effect of phytates you could soak nuts, seeds, and legumes overnight12. Discard the water you soaked them in, and rinse before consuming.

To further assist in your zinc intake consider supplementing with a daily dose of zinc citrate or zinc gluconate.



Iodine plays a crucial role ensuring your thyroid is working properly – and hence all the important metabolic processes it is responsible for.

It can be tricky to know, as a vegan, whether you’re getting enough iodine, because its presence in the plant foods you are eating is highly dependent on the soil in which those plants grew.

One easy way to ensure you are getting a sufficient amount of iodine is to simply use iodised salt. About half a teaspoon per day should meet your needs. Or add seaweed to your diet on a regular basis.

If you don’t feel like using iodised salt or eating seaweed you should consider taking an iodine supplement.


In Conclusion

Unfortunately when it comes to being healthy it’s not quite as simple as just eating your vegetables. A vegan diet obviously has many benefits, but it also does have some downsides – a few I’ve described in this article.

If you have any concerns about your health or the completeness of your diet, the best step would be to have a chat with your doctor. A blood test – which your doctor can order – would be able to tell you the exact state of your nutrition, and would be able to tell you whether there are any areas of concern you should look to focus on, or supplement.

In addition to a blood test you may also find it useful to track your eating habits in an app like Cronometer, which can keep tabs on your intake of a huge number of nutrients and micronutrients. I also wrote an article about the value of tracking, if you would like know more.



  1. The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature
  2. Vitamin B12-Containing Plant Food Sources for Vegetarians
  3. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline
  4. Effect of marine-derived n-3 polyunsaturated fatty acids on C-reactive protein, interleukin 6 and tumor necrosis factor α: a meta-analysis
  5. Omega-3 polyunsaturated fatty acids and vegetarian diets
  6. Review on iron and its importance for human health
  7. Iron and vegetarian diets
  8. The Role of Vitamin D in Human Health: A Paradigm Shift
  9. Comparison of Nutritional Quality of the Vegan, Vegetarian, Semi-Vegetarian, Pesco-Vegetarian and Omnivorous Diet
  10. Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford
  11. Dietary Reference Intakes for Zinc
  12. Considerations in planning vegan diets: children

Gabrielle is an evidence-based vegan coach who believes that health transformation begins when you switch to a plant-based diet. Her mission is to help midlife women eat in alignment with who they are and what they value so that they can lead a happier, healthier and more fulfilling life.

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Written by Gabrielle (hi!), these e-mails will help you on your plant-based journey with useful tips, tricks, facts and inspiration – and perhaps the occasional inappropriate joke thrown in for good measure.

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