Key blood test for vegans & plant-based eaters. Picture arm getting blood drawn and blood draw tubes. Veg Out With Maria

A plant-based diet, especially a whole foods plant-based approach to eating, offers numerous health benefits when well-balanced.

Even if you are trying to make healthy choices, there are nutrients that we can fall short on if we are not paying attention. This holds true for all people, omnivores included, but becomes even more important once you start eating plant-based.

To maintain optimal health on a vegan or plant-based diet, it is always a good idea to be proactive in monitoring your nutritional status. One of the most effective ways to do this is through regular blood tests.

In this blog post, we will explore the key blood tests that vegans and plant-based eaters should consider to ensure they are meeting their nutritional needs and maintaining overall well-being.

Nutritional Considerations for Vegans & Plant-Based Eaters

I first want to address this misconception that diets that include animal products are somehow superior and if you go plant-based you are putting yourself at risk for nutritional deficiencies.

While it is true that it is easier to get certain nutrients eating animals and animal products, this does not mean you cannot meet your nutrition needs on a plant-based diet.

There are a couple of nutrients that are recommended you take in supplement form to ensure you meet your needs. But, by far a plant-based diet – when done right – can provide an excellent source of vitamins, minerals, antioxidants and fiber with much lower levels of saturated fat and zero cholesterol.

Speaking of cholesterol, most people will tell you that dietary cholesterol doesn’t matter. However, we have many studies (not funded by the egg industry) going way back showing otherwise.

This is why the latest Dietary Guidelines for Americans recommends dietary cholesterol intake be “as low as possible without compromising the nutritional adequacy of the diet.”

Potential Nutrient Deficiencies

So, what nutrients should you be concerned about when following a plant-based diet?

Vitamin B12

Most people will agree that any vegan or plant-based eater should supplement with vitamin B12. You cannot get naturally occurring B12 from plant-based sources.

B12 is unique as it is made by bacteria and is commonly found in the GI tracts of animals. Animals also get B12 from ingesting bacteria contaminated food.

Even people who eat meat are often deficient in B12 as there are many medications that can interfere with B12 absorption. Also, as we age our stomach acid production decreases which also inhibits the absorption of B12.

There are a few plant-based sources that fortify with B12. However, since it is difficult to ensure you are getting adequate amounts, it is recommended you take a supplement.

Omega 3

chia, hemp and flax seeds. ALA omega-3 plant based sources.

How can I get omega-3s without eating fish?? The ALA omega-3 from plant foods is often ignored but has been found to have it’s own independent health benefits. It is pretty easy to meet the recommended daily intake of ALA omega 3s on a plant based diet.

There is also some evidence that conversion of ALA to EPA and DHA may be higher in non-meat eaters, but more studies are needed.

Since it is questionable how much ALA is converted into EPA and DHA, it is usually recommended to supplement. Algae based supplements are an excellent vegan source of EPA and DHA omega-3s.

For meat eaters who don’t like to eat fatty fish, it is also often recommended that they take an omega-3 supplement especially with a history of heart disease.

To learn more on this topic definitely read the blog post “best vegan omega 3 sources.”


Since your body is unable to make iodine it is essential that you obtain it either from your diet or from a supplement.

The major food sources of iodine come from seafood, dairy and eggs. Plant-based eaters can get iodine through sea vegetables and iodized salt, but if you don’t consume these regularly then it is recommended that you supplement the RDA (150 mcg) daily.

For more on iodine, check out the blog post “the best vegan sources of iodine.”


It is a common belief that if you don’t eat meat then you are more at risk for iron deficiency because heme iron is better absorbed. While it is true that non-heme iron coming from plant sources is not absorbed as well as the heme iron found in blood and muscle, that doesn’t tell the whole story.

There are several “enhancers” that help increase iron absorption from plant foods. One way is by eating a good source of vitamin C with your meal (if you are eating fruits and vegetables this is easy!).

It’s also been observed that if you follow a plant-based diet you actually tend to consume more iron.  A five year cross-sectional analysis showed that plant-based eaters are actually no more likely to develop iron deficiency anemia than meat eaters1.

A diet high in heme iron has also been associated with increased risk of cancer, heart disease and metabolic syndrome. This is thought to be due to heme iron causing more oxidative stress, contributing to atherosclerosis2,3.

Personally, I have been eating plant-based for 30 years and have never been iron deficient but everyone is different. Women who have heavy menstrual cycles are more at risk for iron deficiency anemia due to higher blood losses and should check their iron status more regularly.

Vitamin D

holding a vitamin d supplement up to the sun

There are very few foods that naturally contain vitamin D. Besides fatty fish, you can find some vitamin D in egg yolks, cheese, beef liver as well as fortified products like milk, plant milks and cereals.

Certain mushrooms contain a little vitamin D2 as well. Most of these sources, however, will not provide you with enough vitamin D to meet your needs.

Another fun way you can get vitamin D is through sunlight. They say the best time of day for vitamin D conversion is around noon or between 10am to 3pm. You really only need about 10-15 minutes of sun exposure to do the trick.

There’s a problem, however, with relying on the sun for adequate amounts of vitamin D. You would think living in Hawaii no one would have vitamin D deficiency, but in fact it is very common!

We often spend most of our time indoors during the day. When we do go outside we often have on sunscreen or clothing which interferes with vitamin D absorption. Just having darker skin color reduces your ability to synthesize vitamin D from the sun.

Also, if you have kidney disease this will interfere with vitamin D absorption because your kidneys are one of the main organs that activate vitamin D into it’s active form so your body can use it.

Everyone, not just plant-based eaters are at risk of vitamin D deficiency. Vitamin D is not only important for bone health and to ensure we are absorbing the calcium from the foods that we eat, but it is also important for our immune system.

I would recommend checking your vitamin D levels regularly, especially if you do not supplement.

The Importance of Variety

Eating a varied diet with different food groups and varieties of plants will not only make your gut happy but will help you better meet your vitamin and mineral needs.

Aim for well-balanced meals which includes lots of produce, a concentrated source of plant-protein and a whole grain or starchy vegetable. This will be helpful in not only keeping you satisfied longer but will provide better blood sugar control and help add variety to your diet.

If you would like to know more on this topic, I created a free supplement & micronutrient guide. This free resource also covers how to eat well-balanced meals on a plant-based diet.

Key Blood Tests For Vegans & Plant-Based Eaters

picture of a gloved hand holding a vitamin D test tube among other colorful blood draw tubes.

So, now that we’ve covered some of the potential nutrient deficiencies on a vegan or plant-based diet, let’s talk blood tests!

I would recommend checking your labs at least annually – more frequently if you have been diagnosed with a known deficiency or are experiencing any kind of symptoms.

Some of these will be routine tests and others you will have to specifically ask for as they are not commonly drawn.

The Following 8 Blood Tests Are Recommended for Vegans:

1. Comprehensive Metabolic Panel (CMP) + HgbA1c

This is a commonly checked panel and looks at the status of your kidneys, liver enzymes, blood sugar, and electrolytes (calcium, sodium, potassium). I add a HgbA1c to get a better overall picture of my blood sugar control (over the past 2-3 months).

2. Complete Blood Count with differential & platelets (CBC)

This is another commonly drawn panel to check for anemia by looking at hemoglobin. It also considers infection (or even potential cancer) by checking your white blood cell count.

If you want to know your iron status specifically, I would add Ferritin and TIBC. A Ferritin test measures how much iron your body stores. TIBC (total iron-binding capacity)is a test that measures how your body transports iron.

3. Lipid Panel

This panel will look at your cholesterol (total, LDL, HDL and triglycerides). While not specific for vegans, it’s always good to know where your cholesterol numbers are. LDL cholesterol is the one you really want to focus on. Optimal levels are below 100 mg/dL, but if you have a history of heart disease you would ideally want your LDL below 70 mg/dL.

4. TSH (Thyroid Stimulating Hormone)

This hormone is made in the brain, actually the pituitary gland, which stimulates the release of important thyroid hormones T3 and T4. These hormones are critical for regulating your metabolism and other important functions in your body.

TSH checks how well your thyroid is working – whether you have too much or too little thyroid hormone. In order for the thyroid to function properly you need an adequate supply of iodine from the diet.

5. Iodine

This is why it is good to check your iodine status to make sure you’re not deficient. I actually checked my iodine levels for the first time recently and found out I was low. Because of that, I now supplement with iodine daily.

6. B12

This is the important one for vegans! If you are taking a B12 supplement your blood level will most likely be high.

While not necessary, if you really were concerned about your B12 status, you can also check MMA (methylmalonic acid) and homocysteine levels. Adding these tests can be a more sensitive approach to detecting early B12 deficiency.

If both MMA and homocysteine are high it points to B12 deficiency. If MMA is normal and homocysteine is high you are most likely deficient in folate (B9).

7. Vitamin D3 (25-Hydroxy D)

Check that sunshine vitamin to make sure you have enough of it! At a minimum your levels should be at least 30 ng/ml, but more ideally between 40-80 ng/ml.

8. Omega 3 Index

This is not a standard test that doctors will order. The Omega 3 Index is insightful because it measures the amount of EPA and DHA in the blood. Most vegans are not going to be at the recommended ideal level.

The omega 3 index test gives you a percentage. It is recommended that your Omega 3 index be >/= 8%, but aiming for at least 5.0% would be a good minimum. Falling to 4% or lower has shown higher risk for heart disease or brain related problems.

I will admit I have not checked my omega 3 index. I just take a daily supplement and eat a lot of ALA rich foods. But, I would be curious to see where I fall on the index.

You don’t need a doctor’s order to check your omega 3 index. You can find several online options to order a test kit. One option is omegaquant.


You most definitely can thrive on a vegan or plant-based diet. The key blood tests discussed in this blog post serve as valuable tools to ensure that you are meeting your nutrient requirements.

Being proactive with your health by addressing potential nutrient deficiencies and eating well-balanced meals including a lot of variety will set you up for success.

It’s important to remember that each individual’s nutritional needs may vary. Consultation with a healthcare professional is strongly encouraged to tailor your dietary choices and supplement recommendations to your unique requirements.

Understanding and monitoring your nutrient levels can be a game-changer in your quest for a healthy and fulfilling lifestyle. With this knowledge and guidance, you can embark on your plant-based journey with confidence!

For more guidance I encourage you to grab my free Plant-Based Supplement & Micronutrient Guide.

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