Serum B12 Levels
Vegans don’t need to get their B12 levels checked merely because they’re vegan. Rather, being vegan means that you should get a regular, reliable source of vitamin B12 from fortified foods or supplements.
About 2% of people do not absorb B12 well, a condition known as pernicious anemia. If you suspect that you might suffer from pernicious anemia, you can be tested for it.
Blood homocysteine level can be elevated in B12, folate, and vitamin B6 deficiency, and is linked with numerous chronic diseases although the role homocysteine plays is controversial. Vegans don’t need to have their homocysteine levels checked merely because they’re vegan, but some doctors recommend that all adults over age 45 have their homocysteine levels checked in order to catch a genetic predisposition to high homocysteine, which can often be successfully treated. It’s more important for vegans to obtain a reliable source of B12 than to have their homocysteine levels checked.
Methylmalonic Acid: Most Specific Test for B12 Status
Methylmalonic acid (MMA) builds up in the system when B12 status is poor. It’s the most specific test for measuring B12 status because B12 is the only necessary co-enzyme needed to keep levels low. MMA can be measured in both the urine and the blood. MMA provides a snapshot of what your B12 status is at a given moment.
Getting your MMA levels tested in the absence of a reliable source of B12 will most likely show it to be elevated. In other words, if you haven’t been obtaining B12, you can avoid the test and just assume your MMA is elevated. If someone is obtaining the recommended amounts of B12 and still has a highly elevated MMA level, it can indicate another condition, such as kidney disease or a B12 metabolism problem that can then be treated under the guidance of a physician.
It’s prudent to have homocysteine levels tested after age 45. Unless you suspect a B12 absorption or metabolic problem, there’s no reason to get MMA or B12 levels tested if you follow the recommendations in Daily Needs.
4 thoughts on “Should I Get My B12 Status Tested?”
First of all, thank you veganhealth.org for your awesome resource. Every vegan needs to know about it!
My question is in regards to checking for Vitamin B12 adequacy in pregnancy. I came across a study that seems to suggest MMA levels were significantly different between the 1st and 3rd and 2nd and 3rd trimesters, while homocysteine levels were not significantly different during pregnancy (here’s the study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5188452/).
Given this research, should pregnant vegans who are concerned about their B12 levels ask for a Homocysteine test instead of MMA? Thank you for your insight!
If someone is trying to determine whether they have enough B12 for a successful pregnancy, then I’d suggest a serum B12 test, unless they suspect they don’t absorb B12 normally in which case they should talk to their doctor. And they should also meet the B12 recommendations for pregnancy.
This article is very educational. I am interested to know if one is vegan but yet blood test shows high on Vitamin B12. What can cause vitamin B12 be high and the dish associated with it. Thanks.
Taking too much vitamin B12 via supplements may cause blood levels to be high. There are also certain health conditions that may result in high B12 levels. We recommend discussing with your healthcare providers.