Why Every Low Vitamin B12 Level Does not Need Fixing

My mother was recently found to have a vitamin B12 level of 122 pg/ml, which is considered abnormally low (normal range - 187-883 pg/ml). A practicing Gujarati Jain, she is anyway considered to be part of an “at-risk” population for vitamin B12 deficiency and so she was asked to start B12 injections followed by tablets.

For the last 20-30 years, the gospel has been that all vegetarians across the world and especially in India and particularly, practicing Jains, are vitamin B12 deficient, due to two reasons; the first is that their only sources of B12 are animal products, milk and eggs, which most vegans and Jains eschew and the second is the multiple research papers in India and abroad that have reported B12 deficiency in between 50-70% of all vegetarian adults, the deficiency worsening with increasing age [1].

In our atmasvasth quest to live long, healthy, it is important to address deficiencies and to add supplements that can improve our healthspan and lifespan.

So it all makes so much logical sense. If you are vegetarian, your B12 levels are likely to be low. If you do a B12 blood test, it will reinforce the presence of B12 “deficiency”. As a result, you will be asked to take supplements either in the form of injections or capsules. Your repeat blood test will likely show “improvement” to so-called normal levels and everyone will be happy that a deficiency has been addressed.

Except…

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The normal range of vitamin B12 on pathology reports is based on an omnivorous Western population. As a result, the vast majority of Indian vegetarians are bound to show a low blood B12 level. This does not mean that they are B12 deficient. It only means that vegetarians, not just in India, but across the world, have a different level of normal, which could be as low as 100 pg/ml [2,3], as against the 148 or 183 pg/ml that is considered the low range of normal, in the pathology reports. Which then means that the so-called “abnormally low” value is not really abnormal, but “normal” for vegetarians, as long as they are not otherwise malnourished.“Low” does not mean “deficient”.

Over the last few days, I have spoken to endocrinologists, neurologists, hematologists, and biochemists, all of whom are broadly in sync with this thinking, as long as the patient they are seeing does not have clinical B12 related problems, either as cause or effect.

So, how can we prove all this? One way is to see whether vegetarians get disproportionate anemia or neurologic complaints, which are clinical manifestations of B12 deficiency. This has not been proven so far. Many physicians would say we should not wait till anemia and neurologic complaints occur and should nip the issue before an actual problem arises, as we do with coronary artery disease, by using statins. The problem with that logic is that, unlike with serum low density lipoprotein (LDL-C) levels and their relationship with coronary artery disease and mortality, where cause and effect are well known and have been proven now for at least 35 years, we have no data to suggest that raising vitamin B12 levels in vegetarians to the so-called omnivore levels, makes a difference to healthspan and lifespan. Nor is there evidence that vegetarians have an increased incidence of dementia or poor cognition as compared to omnivores [4]. What we really need is a normal range for Indian vegetarians, to start with.

The Lindy effect states that the longer a practice has existed in the past, the longer it is likely to survive in the future. Jainism has been around for at least 2500 years. Though the average lifespan across the globe for the last 30,000 years till the late 1800s was just 30-40 years, mainly because of a high infant and childhood mortality, a good number of people did manage to live to the age of 70 and beyond. It is difficult to imagine there would be no documentation of problems related to a vegetarian diet in our traditional medicine books, in those who lived long in the older days.

It is only in the last 50-75 years that the issue of B12 deficiency has reared its head, simply because we have started measuring B12 levels, comparing vegetarians to non-vegetarians. If we apply the Lindy effect, it is likely that Jainism will be around for another 2500 years (unless humankind ceases to exist), in which case, the concept of defining B12 deficiency on the basis of a Western omnivorous population range makes no sense at all.

If you have a medical disease or have anemia or neurologic complaints that your doctor believes is a result of or causes B12 deficiency and needs correction / treatment, that is a clinical judgement call, best left to your doctor. What we our discussing today is the the likelihood that labeling large swathes of vegetarian Indians to be B12 deficient, may not necessarily be true.

What does this mean for you and I? Leaving aside a situation where you have a clinical disease related to B12 deficiency either as cause or effect, there is no data to suggest that you need to routinely test for B12 levels and no evidence that you need routine supplementation, whether vegetarian/Jain or not, whether you have so-called “low” levels of B12 in your blood or not.

Footnotes

1. Singla R et al. Vitamin B12 deficiency is endemic in Indian population: A perspective from North India. Indian J Endocrinol Metab 2019;23:211-4

2. Naik S, et al. Identification of vitamin B12 deficiency in vegetarian Indians. Br J Nutr. 2018 Mar;119(6):629-635.

3. Hannibal L. Invited commentary in response to: 'Identification of vitamin B12 deficiency in vegetarian Indians'. Br J Nutr. 2018 May;119(9):967-969.

4. Iguacel I et al. Vegetarianism and veganism compared with mental health and cognitive outcomes: a systematic review and meta-analysis. Nutr Rev. 2021 Mar 9;79(4):361-381.