Vitamin B12 and Memory

The Importance of Vitamin B12

Vitamin B12 is a critical nutrient to our health. Vitamin B12 is obtained in the diet from eating meat, fish, shellfish, dairy products, and cereals fortified with it.  Vitamin B12 deficiency is associated with blood, neurologic, and psychiatric disorders.

A study recently published in Neurology showed that vitamin B12 deficiency is associated with brain atrophy or shrinkage and cognitive impairments like memory loss.  One of our prior posts discussed brain atrophy related to smoking.

This study analyzed data collected from the Chicago Health and Aging Project (CHAP).  CHAP is a longitudinal study of common chronic health problems affecting older persons, especially of risk factor for Alzheimer’s disease.

The findings from the study in Neurology are not surprising when we consider the role of vitamin B12 in our nervous system.  B12 is essential for myelin sheath development which acts as an insulator surrounding nerves and facilitates transmission of nerve impulses.   If the myelin sheath is damaged or inadequate transmission of nerve impulse slows down impairing function.

Metabolic markers including methylmalonic acid and homocysteine appear to play a role in the development of brain atrophy and cognitive impairment.  Both of those markers are elevated in B12 deficiency.

What are Some of the Symptoms of B12 Deficiency?

Vitamin B12 deficiency symptoms include neuropsychiatric symptoms include memory loss, depression, paresthesias (numbness/tingliness), peripheral neuropathy, irritability, dementia, and in rare cases psychosis.

B12 deficiency can also cause anemia leading to fatigue.  Vitamin B12 benefits are many so it’s important to treat B12 and its causes when possible

What Causes Low B12?

In addition to inadequate intake of B12 from the diet, B12 deficiency is most commonly the result of poor absorption of B12 from the gastrointestinal tract.  Poor absorption of B12 can be caused by a number of gastrointestinal problems including dyspepsia, recurrent peptic ulcer disease, Crohn’s disease and rare conditions like Whipple’s disease and Zollinger-Ellison syndrome.

But the classic cause of B12 deficiency is pernicious anemia, which is an autoimmune disease in which the gastric parietal cells are damaged.  These cells produce intrinsic factor, which is necessary for B12 absorption.

The elderly are more prone to B12 deficiency stemming from dietary factors and also a decline in B12 absorption occurring with aging. Heavy drinkers are also at risk for B12 deficiency.

How is Low B12 Diagnosed?

Low B12 can be diagnosed with a simple blood test in association with the symptoms stated above.  Also, an elevated homocysteine level which is a marker for cardiovascular disease and obtained fairly routinely could suggest a B12 deficiency though folate and B6 deficiencies can also lead to elevated homocysteine levels.  Changes in the size and volume of red blood cells can also be a tip-off that there might be a B12 deficiency.

We typically have about a 2 to 5 year reserve of B12 in our bodies so it does take a while for levels to get depleted.

How Can Low B12 be Treated?

Low B12 can be easily treated with either periodic intramuscular vitamin B12 injections, or it can be given orally.  Today’s oral preparations are effective in raising B12 levels (that was not always the case), but many physicians prefer to administer intramuscular injections.

So B12 deficiency is easy to diagnose and it’s easy to treat.  If you suffer from memory loss consider getting your B12 levels measured.