Blog Post

6 Tests You Should Get if You Are Vegan

Blood test sample tube

Blood and urine tests can tell you a lot about your general health, including if you are getting adequate micronutrients through your diet. This is particularly useful as a vegan since many vitamins and minerals are more difficult to consume in sufficient amounts.

However, these types of test can be done for every single nutrient. For example, testing calcium concentration in your blood does not tell you anything about how much calcium is provided through your diet. This is because calcium in the blood is tightly controlled. If your dietary intake is inadequate, additional calcium is simply taken from your bones.

Zinc is another good example. Dietary intake for zinc is an issue for some vegans, particularly men who have very high requirements. But zinc levels from blood tests do not give insight into the dietary intake and dietary analysis is typically recommended by doctors if inadequate intake is suspected.

This article is going to go through the 6 tests that are actually worth having done as a vegan to make sure your on the right track. I recommend having most of the tests done annually.

1. Iron (Ferritin)

Collection iron rich foods as liver, buckwheat, eggs, parsley leaves, dried apricots, cocoa, lentil, bean, blue poppy seed, broccoli, dried mushrooms, peanuts and pistachios on wooden table.

Iron is essential to a diverse range of bodily functions; oxygen-carrying capacity of the blood, immune function, energy metabolism, and alcohol, and drug metabolism – just to name a few!

The recommended daily intake for iron is almost double for vegans. This is due to the lower bioavailability of iron from plant-based sources. This puts vegans at a higher risk of developing iron-deficiency anemia.

Fatigue is the most common symptom of iron deficiency anaemia, although many people can have mild anemia and not realise. That is why is can be helpful to have iron levels tested once or twice a year.

The most reliable value is serum ferritin. This parameter measures iron storage and shows how good your iron supply is over a prolonged time.

If you mention you are vegan to your doctor, this is likely the first test they will think of. Serum ferritin is tested via a regular blood test.

2. B12 (Cobalamin)

Vitamin B12 food group sources

B12 is another at-risk nutrient on a vegan diet. More so than even iron. That is because plant-based foods contain very little B12 and vegans need to rely on supplementation and/or B12 fortified products.

B12 is lacking in vegan diets as it is synthesized by specific bacteria that reside in ruminant and coprophagic animals only (for example, cows).

While a small amount can be synthesized endogenously (within our own bodies), it is produced in a part of the bowel that does not allow it to be absorbed by our bodies.

Long-term B12 deficiency affects the formation of the protective coating around your nerves and over time can lead to irreversible nerve damage.

The body stores several years’ worth of B12 in the liver so if you have not been vegan for a long time, your B12 levels may look good despite an inadequate dietary intake. B12 deficiency tends to sneak up on people. Often they will have had a few blood tests where B12 was within range but then all of a sudden they are deficient. This is why you should have B12 tests regularly even if you have not had issues in the past.

B12 is also tested via a standard blood test.

3. Vitamin D (Serum 25-cholecalciferol)

Vitamin D supplementation and sun

Vitamin D is a unique vitamin in that it can be obtained through diet or can be produced endogenously (within the body) in the presence of UV rays.

Research has shown that vegans tend to have a lower serum 25-cholecalciferol level than meat-eaters. This is likely because vitamin D-rich foods are all animal-based products, meaning vegans are relying on adequate sun exposure to avoid deficiency.

In many parts of the world where there has been a transition to most of the population working and spending majority of their time indoors, vitamin D deficiency has become more common.

Vitamin D deficiency can lead to poor bone health, fatigue, being prone to illness and infection and even has link to depression and poor mood.

If you are vegan and do not get much sun exposure, it is likely that you will need to supplement. You can confirm you need to supplement via a simple blood test with your doctor.

4. Omega 3 Index Testing

Omega 3 index testing report

Omega-3 fatty acids play an important role in good health. A diet rich in omega-3 is required for maintaining cell membranes, regulating metabolism, and reducing inflammation.

Research also suggests that omega-3 fatty acids likely protect against heart disease due to their impact on cholesterol and blood pressure. Omega-3 fatty acids are particularly important during pregnancy and breastfeeding.

The most efficient way to have a diet rich in omega 3 is by consuming oily fish, such as salmon, several times per week. However, as a vegan or someone on a plant-based diet, efficient sources of omega 3 are lacking.

Foods such as flaxseeds, walnuts, and chia seeds do contain omega 3 but it is in the form of alpha-linolenic acid (ALA).

It is actually omega 3 in the form of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that provides important health benefits.

ALA can be converted into EPA and DHA but the process is not very efficient.

Due to this, vegans typically have significantly lower levels of long-chain omega-3 fatty acids (EPA and DHA) in their blood.

You don’t need a doctor to obtain an Omega-3 Index test. In fact, most doctors won’t or cannot test for omega-3 unless they have access to omega-3 testing kits. You can purchase these online or from some health professionals.

It is a simple finger prick blood test that you send back for testing. The lab will test the EPA and DHA levels in your blood, specifically in the membranes of your red blood cells.

If you have low levels of omega-3, you can supplement with EPA and DHA from marine algae.

5. Urinary Iodine Test

Plant foods contain very little to no iodine. The best options for vegans are iodised salt and nori. However, most vegans don’t typically eat nori every day and you have to be careful about adding too much salt to your food.

So vegans are at higher risk of iodine deficiency.

Iodine is an essential nutrient required for the production of thyroid hormones. These hormones are essential for normal growth, and physical and mental development. We only need a small amount of iodine. Our body can’t store large amounts of iodine so we need a regular intake of this nutrient. 


Iodine deficiency causes a spectrum of mental and physical disorders known as iodine deficiency disorders (IDD).

IDD varies depending on the severity and duration of deficiency and the life stage of the affected person.

Adult iodine deficiency disorders often result in the development of a goiter which is swelling of the thyroid gland.

The best way to test for iodine deficiency is through urine. Majority of iodine is excreted through the urine if there is adequate iodine in the body to support bodily functions. Urine samples can diagnose iodine deficiency when there is not an adequate level of iodine in the urine.

6. Methylmalonic Acid (MMA) & Homocysteine

Research has indicated that the standard serum B12 testing may not always be completely accurate. It is possible for someone who is B12 deficient to have regular B12 levels on a blood test.  

However, increased levels of homocysteine and MMA can be suggestive of a B12 deficiency as well. Therefore, it is best to look at all three biomarkers when deciding if you are getting adequate B12 in your diet or through supplementation.


Those with a vegan or plant-based diet are at a greater risk of developing some common nutrient deficiencies including iron, B12 and vitamin D.

Therefore, it can be a good idea to run a few standard tests each year and ensure that you are making the most out of your diet for health and wellness.

But not all tests are worth getting, and not all tests are a good reflection of dietary intake being sufficient. So rather than getting a bunch of tests that don’t mean much, stick to these 6 for monitoring your vegan diet.

If you want to know more about meeting your nutrient requirements on a vegan diet see our blog post on 9 Things You Should Be Doing on a Vegan Diet.

By Leah Higl

Leah is an accredited practising dietitian from Brisbane. She also competes as an under 75kg powerlifter with Valhalla Strength Brisbane. As both an athlete and dietitian, she spends much of her time developing her knowledge and skills around sports nutrition, specifically for strength-based sports. Although, she works with a range of athletes from triathletes to combat sports and powerlifting. Leah also follows a plant-based diet and her greatest passion is fuelling vegan/vegetarian athletes and proving that plant-based athletes can be just as competitive as their non-vegan counterparts.​