Introduction
When I went vegan I had no idea of the critical importance of vitamin B12. I heard rumblings about vegans having to take B12, but it’s true value never came up during discussions with my doctors, dieticians or other vegans.
The following three posts will be dedicated to providing substantive information on B12 from a South African perspective for adults.
The most important thing to know about being on any plant based diet and Vitamin B12 is this:
You have to take Vitamin B12; this is non negotiable! You have to get adequate Vitamin B12 regularly! Why? because there’s a chance of irreversible brain damage if you don’t get enough.
That’s the big idea, now lets delve into the subtlety.
B12 Tests
Blood Serum B12 Reference Ranges
Serum B12 blood tests are used to gauge B12 sufficiency, however these can be woefully inadequate – that’s because it only tests B12 availability in the blood and not whether it’s used well in the rest of the body. Nevertheless, it’s a good place to start when determining your B12 status.
Here in South Africa we use a different reference range for what is adequate, as compared to other countries.
Here in South Africa we use the reference range of 107-418 pmol/L; however in the US and UK they use the reference range of 200 – 900 pg/mL and 180-1000 pg/mL respectively. Note that the units of the reference ranges are different, making comparisons even more difficult. Also, If you convert the US/UK ranges into SA units of pmol/L, you’ll find they don’t match.
I’ve normalized these differences and tabulated them below.
| International | South African Conversion (pmol/L) | |
| South Africa | N/A | 107.00 – 418.00 pmol/L |
| Australia | 135 – 650 pg/mL | 99.60 – 479.57 pmol/L |
| United Kingdom | 180 – 1000 pg/mL | 132.80 – 737.80 pmol/L |
| United States | 200 – 900 pg/mL | 147.56 – 664.02 pmol/L |
| Japan | 500 – 1300 pg/mL | 368.90 – 959.14 pmol/L |
For a South African plant based eater, this should be worrying, because you may think you’re getting enough B12, whereas you could actually be sub-clinical.
This graphs below sums the international references ranges.
I’ve been tracking my Vitamin B12 serum levels for a while now and here’s a graph of that.
The point of all of this, is that reference ranges are different in other countries, so you might think your B12 levels are fine based on a serum B12 blood test but you could be in trouble. You need to look at better tests, and I’ll address that next.
Homocysteine
There’s an important complicated process that occurs in the body called the methylation cycle, and one of its by-products is homocysteine. Homocysteine is bad because it increases cardiovascular risk, dementia risk, stroke risk and arterial blockages. It’s an important indicator of cardiovascular health and overall wellness. If you’re getting enough B12, Folate and B6 then the process works well and homocysteine levels are kept in check. When anyone of these vitamins are lacking then homocysteine builds up. All the benefits of a plant based whole foods diet could be undone by increased homocysteine due to low B12.
There is a simple blood test to check homocysteine levels, and yet again there’s a reference range issue. In South Africa our reference is anything less than 15 umol/L however other countries use a metric of less than 10 umol/L.
There are also many opinions about what’s best. Dr Gregor of Nutritionfacts mentions that lower levels of homocysteine are better; so that’s what I personally aim for. I have also heard that getting it as close to zero should be the goal but I’m not sure how true this is.
Either way homocysteine is a good indicator as to whether or not you’re getting enough B12.
Choline
Choline is certainly related to homocysteine in my opinion and experience, so I want to address it here. I have a PEMT genetic SNP meaning that I need more choline than others because my body doesn’t synthesize it well.
Not getting enough choline certainly caused issues for me and I found it impossible to get enough from plant foods alone based on my Cronometer data. Unfortunately testing and studies around this nutrient are disturbingly scant especially for vegans. Interestingly, I came across Bryan Johnsons Nutty Pudding video where he mentions Sunflower Lecithin as a safe choline food source. In all my time as a vegan I have never heard that come up. Unfortunately, it’s hard to get a legit Sunflower Lecithin product in South Africa, so I decided to try NOW Foods Sunflower Lecithin 1200mg.
It provides phosphatidyl choline – a usable form of choline for your body as I understand. Once I started taking this to address my choline deficiency I found that my homocysteine values dropped markedly as shown below.
Here’s Bryan Johnsons Nutty Pudding video where the sunflower lecithin comes up.
Cytizoline Cognizin
The pressure in my left eye increased significantly recently. My ophthalmologist reckoned it’s probably due the surgery I had to address a detached retina back in 2018. She’s given me a supplement called Cebrolux NF Neuro which has Cytizoline Cognizin in it which is a precursor to choline.
Without intervention my homocysteine levels were above 10 umol/L. With Omegagenics Methylcare I dropped those levels to below 10 umol/L. With Sunflower Lecithin I dropped it further to 6 umol/L. I’m interested to see if the Cebrolux drops it further.
Methylmalonic Acid
This test is apparently the gold standard for determining if your B12 levels are adequate.
Getting this test done can be very confusing. Most doctors don’t seem to be aware of it, and even the technicians at our labs can get confused. The first methylmalonic acid test I did back in 2022 was a urine test via Pathcare and you had to use the code MMAU.
Now it appears there’s a blood test for it which I haven’t personally done. Neither Ampath or Lancet performs these tests, so you have to get it done by Pathcare under the code CMMA.
What this highlights to me is that vegans and vegetarians are not getting tested, and hence why there’s no awareness of it and why it’s so expensive.
Apparently healthy people have MMA levels below 370 nmol/L, however here in South Africa we use the reference range units of ug/L, so that should convert to 283ug/L. Based on this, my last MMA tests results are bad, so I may need to address this and check it again.
Test Prices
Prevention is better than cure; and prevention is easier to implement if you know how much its costs. So here are all the costs.
| Test | Prices 2020 | Prices 2022 | Prices 2025 | |
| Serum B12 | R188.10 | R254.00 | R290 | |
| Homocysteine | R231.90 | R313.20 | R350 | |
| MMAU | ??? | R957.60 (Urine) | 1052.90 (blood) | |
| Total | R420 | R1 524.80 | 1 692.90 |
I don’t know what the historical 2020 price was for MMAU, but you can clearly see we’re getting screwed overall on prices. The prices increased substantially over the last few years – I suspect this is due to Covid where more medical services are required and patients are getting gouged. Either way, spending cash on B12 testing may be worthwhile to avoid irreversible brain damage.
Other Tests of Value
Red Cell Folate/Serum Folate
I touched B12, Folate and B6 as being important to the methylation process to reduce homocysteine, so it may be of value to test for those.
The labs do offer the red blood cell(RBC) folate and serum folate blood tests.
- RBC folate checks inside the blood cell and shows how much folate a person has taken in over the past few weeks – interestingly red blood cell lifespans are about four months.
- Serum folate shows how much folate has been circulating in the blood over the past few hours. Below are some of my values.
Folate
| Date | Folate Value | Lab | Reference Range |
| 2017-05-27 | 42.5 | Ampath | 10.0-45.1 nmol/L |
| 2024-03-25 | 16.5 | Lancet |
Red Blood Cell Folate
| Date | Red Cell Folate Value | Lab | Reference Range |
| 2020-08-23 | 1920 | Ampath | 317-1894 nmol/l |
| 2025-04-23 | 1952 | Lancet | > 285 nmol/l |
| 2025-11-18 | 1548 | Lancet | > 285 nmol/l |
Vitamin B6
There’s no blood serum test for this as far as I know, but I have come across it in an Organic Acids Tests OATs from the Centre for Human Metabolomics in the North West University and is available from Biometrix.
An important note about Vitamin B6 : You can end up with excessive Vitamin B6 which can be dangerous and lead to neuropathic issues. This is usually due to Vitamin B6 being in so many things these days from multivitamins to fortified foods, so it may be a good idea keeping an eye on this. Not surprisingly, Australia has issued new restrictions on Vitamin B6 because of this.
DNA testing for Genetic SNPs
I mentioned my PEMT genetic SNP earlier. I also have an MTFHR genetic SNP and this means I need much more Vitamin B12 than most. I have the MTHFR 1298CC variant which means I’m only 61% efficient at metabolizing B12. Here’s a great graphic from Dr Jockers.
DNA tests are much more accessible now, and they’ll give you a lot information with respect to methylation(B12, B6, Folate) and much more.
I’ve done the DNAnalysis and the 3×4 DNA tests, and I found them to be very useful.
Cronometer
And indirect way to keep track of these nutrients is by using Cronometer to track your food intake. This is a simple powerful way of getting a sense of the levels of these nutrients. It’s not definitive but I do think it’s very valuable.
Conclusion
When I went vegan I knew nothing of Vitamin B12, then I experienced problems and I learned just how critical this vitamin is. Now after having studied this vitamin, I feel more aware but still very much in the dark about it. Neither our healthcare professionals or the vegan community know much about testing, consequences and specially the causes of B12 deficiency – and that’s what I’ll address in the next post.
My B12 Blood tests
Serum Vitamin B12
| Date | Value | Lab | Reference Range | Lifestyle |
|---|---|---|---|---|
| 2017-05-27 | 222 | Ampath | 107-418 pmol/L | Vegan |
| 2019-02-11 | 95 | Ampath | 107-418 pmol/L | Vegan |
| 2020-09-07 | 124 | Ampath | 107-418 pmol/L | Vegan |
| 2020-11-03 | 114 | Ampath | 107-418 pmol/L | Vegan |
| 2020-12-15 | 407 | Ampath | 107-418 pmol/L | Vegan |
| 2021-01-07 | 353 | Ampath | 107-418 pmol/L | Vegan |
| 2021-03-12 | 226 | Ampath | 107-418 pmol/L | Vegan |
| 2021-04-06 | 279 | Ampath | 107-418 pmol/L | Vegan |
| 2021-05-05 | 248 | Ampath | 107-418 pmol/L | Vegan |
| 2021-10-04 | 224 | Ampath | 107-418 pmol/L | Vegan |
| 2022-02-26 | 431 | Ampath | 107-418 pmol/L | Vegan |
| 2022-08-23 | 318 | Ampath | 107-418 pmol/L | Vegan |
| 2023-01-04 | 307 | Ampath | 107-418 pmol/L | Vegan |
| 2023-08-31 | 298 | Ampath | 107-418 pmol/L | Vegan |
| 2023-10-07 | 544 | Ampath | 107-418 pmol/L | Vegan |
| 2023-10-25 | 518 | Ampath | 107-418 pmol/L | Vegan |
| 2024-01-20 | 453 | Ampath | 107-418 pmol/L | Non-Vegan |
| 2024-03-25 | 488 | Lancet | > 138 pmol/L | Non-Vegan |
| 2024-11-16 | 466 | Ampath | 107-418 pmol/L | Non-Vegan |
| 2025-04-23 | 806 | Lancet | > 138 pmol/L | Non-Vegan |
| 2025-05-28 | 508 | Ampath | 107-418 pmol/L | Non-Vegan |
| 2025-09-30 | 498 | Lancet | > 138 pmol/L | Non-Vegan |
| 2025-11-18 | 440 | Lancet | > 138 pmol/L | Non-Vegan |
Homocysteine
| Date | Value | Lab | Reference Range | Lifestyle |
|---|---|---|---|---|
| 2020-11-04 | 13 | Ampath | < 15 umol/L | Vegan |
| 2020-12-15 | 11 | Ampath | < 15 umol/L | Vegan |
| 2021-01-27 | 13 | Ampath | < 15 umol/L | Vegan |
| 2021-03-12 | 15 | Ampath | < 15 umol/L | Vegan |
| 2021-04-06 | 12 | Ampath | < 15 umol/L | Vegan |
| 2021-05-05 | 9 | Ampath | < 15 umol/L | Vegan |
| 2021-10-04 | 13 | Ampath | < 15 umol/L | Vegan |
| 2022-02-26 | 10 | Ampath | < 15 umol/L | Vegan |
| 2022-08-23 | 11 | Ampath | < 15 umol/L | Vegan |
| 2023-01-04 | 10 | Ampath | < 15 umol/L | Vegan |
| 2023-08-31 | 18 | Ampath | < 15 umol/L | Vegan |
| 2023-10-17 | 12 | Ampath | < 15 umol/L | Vegan |
| 2023-10-25 | 11 | Ampath | < 15 umol/L | Vegan |
| 2024-01-20 | 14 | Ampath | < 15 umol/L | Non-Vegan |
| 2024-04-13 | 9 | Ampath | < 15 umol/L | Non-Vegan |
| 2024-11-16 | 12 | Ampath | < 15 umol/L | Non-Vegan |
| 2025-03-01 | 8 | Ampath | < 15 umol/L | Non-Vegan |
| 2025-10-01 | 6.1 | Lancet | < 15.4 umol/l | Non-Vegan |
| 2025-11-18 | 6.5 | Lancet | < 15.4 umol/l | Non-Vegan |
Photo by Dose Juice on Unsplash
References
http://www.unitslab.com/node/141
B12 Absorption – Best Forms Of Vitamin B12 For Maximum Absorption
Spirulina – Is It Blocking Your B12 Absorption?
Urinary Methylmalonic Acid/Creatinine ratio: A gold standard test for tissue vitamin B12 Deficiency
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