Blood test for vegans and vegetarians
Eating plant-based works perfectly well. There is just a small set of nutrients that is harder to get, and you can measure those instead of guessing about them.
This is not an argument against plant-based eating. It is a list of four values known to come out low more often on a plant-based pattern. Knowing where you stand tells you whether you need to supplement, and whether what you already take is landing.
The four that matter
Vitamin B12
Found almost only in animal products. Your liver holds a store that can last years, which means a deficiency builds slowly and you notice it late. If you supplement, you mostly measure your supplementation. See vitamin B12.
Ferritin and iron status
Iron from plant sources absorbs less well than iron from meat. Vitamin C with the same meal helps, tea and coffee alongside inhibit it. Ferritin shows your store, which can be low while haemoglobin is still normal. See iron and ferritin.
Vitamin D
Not a vegan issue but a Dutch one. Between roughly October and April the sun sits too low to produce enough. Dietary vitamin D does more often come from animal sources, which lowers your baseline. See vitamin D.
Omega-3 index
EPA and DHA are mainly found in oily fish. Plant-based you take in ALA, and your body converts only a small share of it. The omega-3 index measures the share of EPA and DHA in your red cells, and it responds directly to what you eat or supplement. Algae oil is the plant-based route.
All four, or a selection?
Message how long you have eaten plant-based and what you supplement. If you have been supplementing well for years, a smaller set is often enough and Mario will say so.
Reachable Monday to Saturday, 08:00 to 18:00. An appointment can usually be scheduled within a few days.
All markers at a glance
Packages that fit
When to measure
- After your first year of eating plant-based. Before that you are still living off your store.
- At the end of winter for vitamin D, around February or March.
- After 8 to 12 weeks of supplementing, to see whether your dose is landing.
- Annually if nothing else changes.
Frequently asked questions
Do I have to supplement B12 as a vegan?
Without fortified products your store eventually depletes.
How fast depends on your starting store. Measuring tells you where you stand. For dosing advice see a dietitian or your GP.
Can I keep my iron up on a plant-based diet?
Often yes, but absorption is lower.
Vitamin C with the same meal helps, tea and coffee alongside inhibit. Ferritin shows whether it is enough in your case.
Why is the omega-3 index not in the vitamin package?
Because it is a separate assay.
The index is measured in red blood cells and has a longer turnaround, up to 14 working days. You can add it to the same draw.
I have been vegetarian for years. Is this still relevant?
The risks are smaller but not zero.
Vegetarian diets usually supply some B12 and iron through dairy and eggs. Ferritin and B12 remain the two most useful to check once.
Do I need to fast?
Not for these four.
B12, ferritin, vitamin D and the omega-3 index are not fasting-dependent. If glucose or triglycerides are added, then yes.
Note: a blood test gives you insight and direction. It does not prove or rule out a condition on its own. Results are meant for prevention and for tracking change over time, not as a diagnosis. For symptoms or values outside the reference range, see your GP.