There are a number of blood tests a vegan should do to check his/her health status, and each one should choose accordingly to their nutritional behavior. I have compiled from both internet and my knowledge (and experience) to provide the following list. Some may overlap with the previous answer, but others may have been missed before. This list takes account that each body functions differently and the same diets to two different people will not reflect the same health test results.
CBC - Complete Blood Count (plus differentials and platelets) - to determine the general level of health
CMP - Comprehensive Metabolic Panel - vegan or not, these tests should be carried out frequently, perhaps yearly. This includes calcium and glucose, alongside bilirubin, BUN, ALP, AST (and others) providing a good picture of one's health status.
Serum Iron, Total Iron Binding Capacity (TIBC), and Ferritin - getting enough iron without supplements may be tricky, since some diets may inhibit its absorbtion. These blood tests are cheap and should prevent any type of anemia
Folic acid (blood or erythrocyte) - to quote:
Data from the EPIC-Oxford study, which compares different dietary groups, showed that vegan participants had the highest levels of folate in their blood. However, being vegan is no guarantee that you’re getting enough folate!
This test is more useful for vegan women who would want to have a child, although they should already supplement it. Otherwise, the test may be taken more sparsely (especially if one supplements accordingly).
Blood Vitamin D - Vegans have concerning low vitamin D levels
Although there are controversies, vegan diet may rarely lead to formation of kidney stones (although it may prevent kidney disease). Urinalysis, urinary calcium and urinary uric acid should be thus assessed to make sure one is not liable to kidney stone formation, especially if eating foods high in oxalate.
A report from the EPIC-Oxford cohort found that vegans had the lowest average vitamin D levels of any diet group, so blood tests for this vitamin and supplementation (plus sunbathing) should be carried accordingly
- Blood lipid panel (total cholesterol, LDL, HDL, VLDL, TG) are important tests for every person, given that multiple dietary, genetic and behavioral (e.g. exercise) factors influence their metabolism. Despite evidence showing vegan diets to be generally beneficial, vegan diets may lower good HDL cholesterol; also, take this article discussing how high levels of glycine in vegan diets may lower bio-availability of methionine and, in turn, alter (in a negative way) plasma lipid levels.
I would not take the following (more expensive) tests unless other blood tests are out of limits or/and I am worried that I do not eat a balanced diet and take the proper vitamins. Or if some health problems are present. Nonetheless, to be extra cautious, these tests could be taker more rarely, i.e. once every few years (but first after a few months after switching to veganism)
Vitamin B12, homocysteine, Methylmalonic Acid (MMA) - I would not worry about these if I take trustwothy B12 supplements as recommended (e.g. low doses twice per day, a high dose once a day, or a very high dose once a few days)
Blood EPA/DHA levels - I would not worry about these if I take algal omega-3 supplements and a daily dose of linseed oil ALA omega-3 (and to also compensate for intakes of omega-6), especially since
There is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians.
I would add that each body converts ALA to EPA and DHA in various amounts.
Altogether, (more) invasive tests should be carried only at MD's recommendation.
