ROCHESTER, Minn. — Mayo Clinic experts routinely recommend that older adults consider B-12 supplements or food fortified with this critical vitamin. The September issue of Mayo Clinic Health Letter covers the importance of vitamin B-12, problems associated with vitamin B-12 deficiency and how this condition can be avoided.
Vitamin B-12 plays a role in red blood cell formation, cell metabolism, nerve function and bone health. A deficiency of vitamin B-12 can be associated with tingling or prickly feelings in legs or hands, difficulty walking, forgetfulness, changes in personality, weakness and anemia (shortage of red blood cells).
From 5 to 15 percent of adults have vitamin B-12 deficiency. It develops slowly and is more common with increasing age. Since the symptoms are similar to many other conditions associated with aging, it's sometimes overlooked.
The primary natural sources of vitamin B-12 are meats, fish, shellfish, eggs and milk. Some breakfast cereals are fortified with vitamin B-12. Deficiency can occur due to diet. But most often, a deficiency occurs when the body doesn't properly digest and absorb vitamin B-12. Causes can be changes due to aging, celiac disease, Crohn's disease or prolonged use of some medications used to treat gastroesophageal reflux disease or other stomach problems. The diabetes drug metformin also is associated with vitamin B-12 deficiency.
Diagnosis of vitamin B-12 deficiency typically involves several blood tests. Once it's diagnosed, other testing may be indicated to look for an underlying cause.
Treatment involves addressing the underlying condition, if possible. A doctor may recommend injections of high doses of vitamin B-12 or high-dose oral supplements. The body responds rapidly to high-dose vitamin B-12, with nerve symptoms subsiding over weeks to months. Typically, the degree of improvement is influenced by the severity and duration of the nerve symptoms. In advanced cases, nerve problems may not improve.
People who eat meat or cereals fortified with vitamin B-12 are likely getting the recommended daily intake of 2.4 micrograms. Older adults may benefit from a daily supplement to prevent deficiency. Vitamin B-12 is not toxic so there are no concerns about an overdose.
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