B12 – Are you getting enough for your Brain and your Bones?

Vitamin B12 is one of the most commonly deficient vitamins and affects your whole body, from your brain to your bones. The older you are, the more you need. B12 deficiency is extremely common among people over the age of 60, but it appears that even slightly lower than normal levels may be detrimental.


In a study of people between the ages of 61 and 87, those with lower levels of B12 showed greater degrees of brain size shrinkage. 1 Two in five people over the age of 61 had a level of B12 that was associated with accelerated brain shrinkage and memory decline. However, none of these subjects were diagnosed as classically B12 deficient. Lower B12 status correlates with poor memory scores. Less B12 means higher homocysteine levels, and the higher a person’s homocysteine level, the greater the risk for dementia or Alzheimer’s. 2,3

However, low B12 status is rarely properly checked for, and there are good grounds for making it a routine test, along with homocysteine, for anyone over the age of 60. This is because its ability to be absorbed becomes worse with age. The usual means of checking is to measure B12 levels in the blood plasma, but this is a very crude measure. Also, it is becoming clear that having a level in the low end of the so-called ‘normal’ range is associated with declining memory.


In Japan they start treating for B12 deficiency from below 500 ng/L; in the UK, the cut-off point is typically 150 ng/L. A more accurate test looks for methylmalonic acid (MMA), which is a more reliable marker for B12 deficiency and becomes high if you are deficient. The MMA test is more widely available. This chemical only accumulates if you are deficient in B12, or not using it efficiently. Another alternative is to test HoloTransCobalamin (HoloTC) which, if low, indicates B12 deficiency.

If you want to be sure of your B12 status it is best to get your MMA level tested. This should be below 0.37 mol/L. If your homocysteine level is also high, it is wise to assume you are not getting enough vitamin B12.


One interesting discovery is the link between homocysteine, low B12 levels and bone and joint health. Over the last five years, there have been more and more studies linking high homocysteine and low B12 levels to increased risk of fractures, osteoporosis, and decreased bone mass density, particularly in women. It appears that homocysteine, which is elevated by B12 deficiency, can actually damage bone by encouraging its breakdown and interfering with the collagen matrix (which holds bone together). Collagen is made from vitamin C, which is yet another reason why I recommend a daily intake of 1000 mg taken twice a day.

High homocysteine levels are linked to most inflammatory diseases, since homocysteine promotes the release of pro-inflammatory agents in the body.4 Homocysteine levels are frequently found to be much higher in rheumatoid arthritis sufferers5 as well as those with ankylosing spondylitis, which is an inflammatory arthritic disease of the spine.6

Since rheumatoid arthritis is a ‘systemic’ disease, where the whole body’s chemistry is out of balance, with many tissues and organs other than the joints being affected, one would suspect that homocysteine plays a leading role in the disease. And it does. Research from the Department of Biochemistry at the University Hospital in Madrid, Spain, examined the homocysteine scores of women with rheumatoid arthritis versus those without. There was a massive difference. The average homocysteine score for those with rheumatoid arthritis was a sky high 17.3 μmol/l, compared to 7.6 for those without!7


Other research groups have found similar differences, especially among rheumatoid arthritis sufferers with a history of thrombosis or abnormal clotting of the blood.8 Homocysteine is now thought to damage joints and other tissues directly.9 All of this suggests that reducing homocysteine may well help keep your bones and joints healthy. Yet, disappointingly, very little research has yet been done to test the homocysteine theory on arthritis. An exception occurred in 1994 when forward-thinking researchers from the highly esteemed American College of Nutrition in Clearwater, Florida, did a study on B12 and folate supplements. The research group consisted of 26 people who had been suffering from osteoarthritis of the hands for more than five years, and had been taking non-steroidal anti-inflammatory, pain relieving drugs (NSAIDs). B12 and folate were shown to work together to help reduce high homocysteine levels.

The results showed that people with arthritis who took the vitamins in place of the NSAIDs had less tenderness in their hand joints and similar improvement in their ability to grip objects when compared with those just taking NSAIDs. Additionally, they avoided the notorious side effects seen with the use of NSAIDs.10 NSAIDs can cause serious reactions, including premature death from kidney failure, ulcers and bleeding in the digestive tract, and they cost considerably more than B12 and folate supplements.


A common sign of B12 deficiency, known as pernicious anaemia, is chronic fatigue. Other tell-tale signs are brain fogs, breathlessness (sighing and gulping), brittle nails with ridges, pins and needles, a swollen or sore tongue, balance problems, and unsteadiness. These can be experienced by young and old alike since some people have an innate difficulty absorbing vitamin B12.


B12 is only found in animal foods such as meat, fish, eggs and milk. But only increasing the intake of fish and milk is linked to increasing B12 levels.11 Increasing consumption of meat and eggs does not seem to be anything near as effective for improving your B12 status. My advice is to eat more fish and also to supplement at least 10 mcg if you are younger than 50, 50 mcg if you are over 50, and 500 mcg or more if you have a raised homocysteine level (above 9 mmol/L). While no one can actually use 500 mcg, these high levels become necessary as absorption of B12 declines. One way to improve B12 absorption is to give a special form of B12, either methylcobalamine or glutathionylcobalamine.12

The reason for recommending this seemingly very high level, given that the recommended daily allowance (RDA) is only 2.5 μg, is that only these kind of daily intakes help to correct deficiency. That’s what a group of researchers in Holland found when they investigated how much B12 you need to take in to correct mild B12 deficiency. Only doses of 647 – 1032 μg of B12 were associated with correcting deficiency. In their words, ‘the lowest dose of oral B12 required to normalise mild B12 deficiency is more than 250 times greater than the United States’ RDA’. 13 The RDA in Britain is only 1 mcg! So much for a well-balanced diet giving you all the nutrients you need!

If you think you may be B12 deficient, there are online questionnaires you can take to help you find out. Check out the Pernicious Anaemia Society website (www.pernicious-anaemia-society.org) for their symptoms checklist. However, these don’t take the place of getting tested with your local doctor.


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B12 – Are you getting enough for your Brain and your Bones?

Patrick Holford
About The Author
- He, together with his team, carried out Britain's biggest-ever health and diet survey, the 100% Health Survey, which has now been completed by over 60 000 people. His book, The 10 Secrets of 100% Healthy People, portrays the fascinating insights provided by the survey and his 30 years study of good health and how to achieve it.