B12 Deficiency Linked to Cognitive Decline, and more

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Research is showing that many older people could benefit from getting more vitamin B12 than they currently do. Some 10% to 15% of people over age 60 are outright deficient, and many more are borderline deficient. Their blood levels of B12 are in what’s called a “low-normal” range, and if their doctor isn’t up on the latest research, they won’t be treated for B12 deficiency with supplemental B12. That’s a shame, because research now shows that low B12 can cause all sorts of problems, and that getting an optimal amount can boost brain power, lift the mood, improve bone density,and help to maintain healthy hearing and eyesight.

Here’s what the latest research shows vitamin B12 does:

Brain health: One study found that older people with lower-than-average B12 levels were correlated with signs of brain shrinkage, an early sign of impaired cognitive function and Alzheimer’s disease. Even B12 levels that are above the traditional cutoff for deficiency — and seemingly adequate — may impact cognition in older people. B12 is needed to maintain the fatty myelin sheath that wraps around and protects nerves, including nerve cells in the brain.

Eyesight: Harvard researchers found favorable results for women aged 40 and older who supplemented with 1,000 micrograms of B12. They attribute it to lower levels of the amino acid homocysteine and better antioxidant effects. Both improved blood vessel function in the retina of the eye.

Keeps your hearing sharp. There may be a connection between B12 deficiency and hearing. One study found that low blood levels of vitamin B12 were linked to a higher risk of hearing loss in women in their 60s. Toxic homocysteine may damage the delicate cells that transmit sound waves in the inner ear.

Mental health: A study from the National Institute of Aging found a high incidence of depression in women with low B12 levels. B12 is needed for the production of important brain neurotransmitters such as serotonin, norepinephrine and melatonin, the “sleep” hormone.

Maintains strong bones. In the Framingham Offspring Osteoporosis Study, people with low B12 levels had lower-than-average bone mineral density. B12 may build stronger bones by aiding osteoblasts, the cells that build bone, and by lowering homocysteine, which weakens bone by interfering with collagen cross-linking, the molecular “stitching” that makes bones strong and flexible.

Older people often don’t absorb enough B12, even when they get enough in their diet. Some experts believe that blood B12 levels should be at least 350 picomoles/liter (or 44 picograms/mL.) It’s a good idea to have your blood level checked if you are over age 50.

Symptoms of B12 deficiency include fatigue, depression, numbness and tingling of the arms and, most commonly, the legs, difficulty walking, memory loss, disorientation, tongue soreness, and appetite loss. Because so many older people are borderline deficient, more experts are recommending anyone age 50 or older get at least 100 to 400 mcg a day of B12.

Your risk for deficiency increases as you get older, and the consequences for your health can be devastating. Taking a B12 supplement is good insurance against deficiency, and B12 supplements are also very well tolerated. It’s a good idea to ask your doctor to check your B12 levels to determine whether you may have a severe deficiency that warrants much higher levels of supplementation.