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Blood tests for vegan and plant-based diets

Vegan diets have grown in popularity in recent years, with more people than ever before choosing to follow a plant-based lifestyle. The number of vegans in Britain has risen dramatically, with more than 3.5 million Britons now identifying as Vegan. The Vegan Society has noted veganism as one of Britain’s “fastest growing lifestyle movements”.

What is veganism?

A vegan or plant-based diet involves eating only food products made from plants and avoiding all foods or food products sourced from animals.

For many vegans, their dietary choices centre around:

  • Being conscious of the earth’s resources and environment
  • Ethical issues about animal care
  • Concerns about the health impact of widespread antibiotics and growth hormone use in animal farming
  • The health advantages of a plant-based diet


How does veganism differ from vegetarianism?

The main difference is that vegetarians do not eat meat or fish, but will continue to consume dairy products and eggs. Vegans consume no animal produce at all.

What are the health benefits of a vegan lifestyle?

A more varied and balanced diet

Eliminating meat and animal products will inevitably lead you to rely more heavily on other foods. Substitutes usually take the form of whole grains, fruits, vegetables, beans, peas, nuts and seeds.

Studies have consistently reported that well-planned vegan diets tend to be higher in dietary fibre, magnesium, potassium folate, vitamins A, C and E, and phytochemicals (beneficial plant compounds).

Weight management

Generally speaking, vegan and plant-based diets are lower in calories. This makes them effective at promoting weight loss, without the need to actively focus on calorie restriction.

Several observational studies show that vegans tend to have lower body mass indices (BMIs) than non-vegans. Plus, several randomised controlled studies — the gold standard in scientific research — have reported that vegan diets are more effective for weight loss, than the reference diets they were compared to.

Reduced diabetes risk

Going vegan may also have benefits for the prevention of type 2 diabetes. Vegans usually have lower blood sugar levels, and an estimated 50–78% lower risk of developing type 2 diabetes.

Reduced risk of high blood pressure and heart disease

A well-planned vegan diets typically consists of fresh fruits, vegetables, legumes and fibre – all of these foods are are linked to a lower risk of heart disease.

Observational studies comparing vegans to the general population report that vegans may benefit from up to a 75% lower risk of developing high blood pressure and an up to 42% lower risk of dying from heart disease.

Reduced cancer risk

According to the World Health Organization, about one-third of all cancers can be prevented by factors within our control, including diet.

Vegan diets are made up of lots of fresh fruits and vegetables, and a recent review of 96 studies found that vegans may benefit from a 15% lower risk of developing or dying from cancer, credit to their nutrient rich diet.

Studies have also shown that regularly eating legumes may reduce your risk of bowel cancer by about 9–18% and eating soy as a meat replacement may provide some protection against breast cancer.

Are there any health risks associated with a vegan lifestyle?

Animal products are important sources of protein, non-saturated fats, iron, vitamins, and minerals in standard Western diets.

Vegans are need to find alternative sources of these nutrients, and poorly planned vegan diets may provide insufficient amounts of the following nutrients:

Beneficial (Omega 3) fats

Diets that do not include fish, eggs, or sea vegetables (seaweeds) generally lack the beneficial Omega 3 fats EPA and DHA, which are important for optimal nervous system, cardiovascular, eye and joint health.

Omega 3s also keep inflammation levels in the body low. Humans are able to convert the plant-based Omega 3 fat α-linolenic acid, found in nuts and seeds into EPA and DHA, albeit with a fairly low efficiency and not in the amounts required to achieve the aforementioned benefits.

Compared with non-vegetarians, vegetarians, and especially vegans, tend to have lower blood concentrations of EPA and DHA. Vegans can obtain DHA and EPA from micro-algae oil supplements, as well as from foods fortified with DHA and EPA.

Vitamin B-12

This nutrient is needed to protect nerves and produce healthy red blood cells. Vegans typically have a higher prevalence of vitamin B-12 deficiency.

Vitamin B-12 deficiency can result in anaemia, fatigue, mood disturbance, memory and concentration difficulty, and abnormal neurological symptoms such paresthesia (pins and needles). Introduce B-12-fortified plant foods such as, fortified soy, cereals, seaweed and nutritional yeast into your diet to help top-up your intake of vitamin B-12.

Your Vitamin B-12 intake can be increased with vitamin supplements.


The purpose of iron is to help absorb oxygen into the blood and transport oxygen to the cells in the body. There is no greater risk of iron deficiency if you’re a vegan or vegetarian; in fact, most people on plant-based diets actually get more dietary iron. However most people on plant-based diets usually have lower ferritin levels, which is a marker of how much iron is stored in the body.

This is because heme-iron (found in meat and animal sources of protein), is absorbed in substantially higher quantities by the body than non-heme iron found in plant foods. This means that vegans have to eat substantially more non-heme iron to get the equivalent amount iron from animal sources.

Low iron is a relatively common problem for women of childbearing age, and it’s definitely worth keeping an eye on your levels, particularly if you have heavy periods, or you are struggling with fatigue.

Dried beans and dark leafy greens are rich sources of iron and vitamin C, which improves the absorption of non-heme iron. Using a cast-iron skillet to prepare meals is a good way to increase the iron content of food.


This mineral is crucial for bone health and skeletal development. Vegans are at risk of falling short of the recommended daily intake for calcium. Eating more tofu, tahini, almonds and green, leafy vegetables can help to top up calcium levels.

Vitamin D

This vitamin protects against multiple cancers and chronic diseases, and helps to strengthen immunity, bones and teeth. Regularly consuming more vitamin-D-fortified foods and spending time in the sun can help to supplement the natural production of vitamin D in the skin. In the UK, sun exposure in is inadequate during the winter months to ensure sufficient production of Vitamin D in the skin.

According to guidelines issued by Public Health England, adults and children over the age of one should have 10 micrograms (mcg) of vitamin D every day during the winter months. This means that some people may need to consider taking a supplement, or ensure a sufficient intake of foods fortified with vitamin D.


Deficiency of this mineral can lead to hair loss, poor healing of wounds, immunological problems, skin problems and reproductive hormone imbalance. Vegans are often considered to be at risk for zinc deficiency due to the high phytate content of a typical vegan diet. Phytates – a common component of grains, seeds, and legumes, bind zinc and decreases its availability for absorption by the body.

Nuts and seeds are excellent sources of zinc, some of the best being pumpkin seeds, sunflower seeds, walnuts, cashews, almonds, pecans, chia seeds, and hemp seeds.


Most people know that the maintenance of healthy muscles requires a sufficient intake of protein. However, all of our body’s tissues and organs require protein for general maintenance, and for making new cells. Our bodies require different types of protein in different tissues and for different functions. Proteins are large molecules that are made up of building blocks called amino acids. When we eat proteins, they are broken down by our digestive tract into individual amino acids, which are then absorbed into the bloodstream.

Amino acids are transported to our organs and tissues where they are rebuilt to form the exact protein we need, in the right place. Our bodies are also capable of converting one type of amino acid to another. There are certain amino acids which are cannot be produced by the body, a.k.a. essential amino acids (EAAs), and which can only be found from dietary sources. All animal-based proteins are complete sources of protein as they contain all of the EAAs required by the body. EAAs are not all present in any single plant-based food.

Replacing meat in the diet should be done by introducing (or increasing) intake of a range of vegan foods to make sure all EAAs are covered. Knowledge of which foods to mix together is therefore crucial for maintaining optimal health and functioning. It is also important to stay away from nutrient-poor, fast-food vegan options. Instead, build your diet around nutrient-rich whole plants and fortified foods.

How do I know if I have any nutritional deficiencies?

Blood tests are a good way of confirming optimal internal organ function and screening for nutrient deficiencies.

The London Doctors Clinic Vegan Blood Profile includes:

  • Full Blood Count (FBC)
 – detailed information about your red and white blood cells, and can be used to detect conditions such as anaemias caused by iron and/or vitamin-B12 deficiency.

  • Vitamin-B12, Folate – a measurement of vitamin-B12 and Folate in your blood.
  • Iron and Ferritin – a measurement of iron and ferritin (a marker of the body’s iron stores) levels.
  • Omega 3 & 6 – a measurement of Omega 3 fats (DHA and EPA) and the ratio of Omega 3 to Omega 6 fats. Omega 3 fats are anti-inflammatory, whereas Omega 6 fats tend to be pro-inflammatory. A ratio of 2:1 is considered to be ideal.
  • Lipids – this test measures levels of Cholesterol and it’s sub-fractions including HDL/“beneficial” cholesterol, and LDL/“harmful” cholesterol
  • HBA1C
 – the Glycosylated Haemoglobin blood test indicates how well blood sugar levels have been controlled in the preceding 6-8 weeks. The test can be used to identify individuals with diabetes or those at a higher risk of developing diabetes (“pre-diabetes”) due to frequently eating nutrient-poor, sugar-rich fast-food vegan options


How often should I have this test?

For most people it would be beneficial to have these parameters checked annually. Your GP is the best person to determine whether you need additional tests, or more frequent testing, depending on your health status and individual needs. The results will help determine whether you require vitamin or mineral supplements.

For a Blood Test Vegan Profile, book an appointment for at one of our central London locations. The cost of the tests and investigations is £280 in addition to the consultation price. In the notes section of the booking form add ‘Blood Test Vegan Profile’ so we know what testing to carry out.




Written by: Daniel Fenton, Clinical Director

Published: February 2022

Review: February 2023


Please note the cost does NOT include the standard consultation price starting from from £89.