Interesting. I’ve found my general mood and energy levels are increased when I regularly consume B vitamins. I prefer taking a coenzymate B Complex, which includes B12.
the ability to absorb B12 naturally present in foods depends on the presence of adequate stomach acid, the enzyme pepsin and a gastric protein called intrinsic factor to release the vitamin from the food protein it is attached to. Only then can the vitamin be absorbed by the small intestine. As people age, acid-producing cells in the stomach may gradually cease to function, a condition called atrophic gastritis.
A century ago, researchers discovered that some people — most likely including Mary Todd Lincoln — had a condition called pernicious anemia, a deficiency of red blood cells ultimately identified as an autoimmune disease that causes a loss of stomach cells needed for B12 absorption. Mrs. Lincoln was known to behave erratically and was ultimately committed to a mental hospital.
“Depression, dementia and mental impairment are often associated with” a deficiency of B12 and its companion B vitamin folate, “especially in the elderly,” Dr. Rajaprabhakaran Rajarethinam, a psychiatrist at Wayne State University School of Medicine, has written.
He described a 66-year-old woman hospitalized with severe depression, psychosis and a loss of energy and interest in life who had extremely low blood levels of B12 and whose symptoms were almost entirely reversed by injections of the vitamin.
European researchers have also shown that giving B12 to people deficient in the vitamin helped protect many of the areas of the brain damaged by Alzheimer’s disease. In a two-year study at the University of Oxford of 270 people older than 70 with mild cognitive impairment and low B12 levels, Dr. Helga Refsum, a professor of nutrition at the University of Oslo, found reduced cerebral atrophy in those treated with high doses of the vitamin.
“A B12 vitamin deficiency as a cause of cognitive issues is more common than we think, especially among the elderly who live alone and don’t eat properly,” Dr. Rajarethinam said.
The academy estimates that between 10 percent and 30 percent of people older than 50 produce too little stomach acid to release B12 from its carrier protein in foods, and as the years advance, the percentage of low-acid producers rises.
But many people do not know they produce inadequate amounts of stomach acid. In fact, evidence from a study of young adults called the Framingham Offspring Study suggests that insufficient absorption of B12 from foods may even be common among adults aged 26 to 49, so the following advice may pertain to them as well.
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While a B12 deficiency can take years to develop, encroaching symptoms can be distressing and eventually devastating. It can also be challenging to link such symptoms to a nutrient deficiency.
In an online posting in July, David G. Schardt, the senior nutritionist for the Center for Science in the Public Interest, noted that symptoms of B12 deficiency include fatigue, tingling and numbness in the hands and feet, muscle weakness and loss of reflexes, which may progress to confusion, depression, memory loss and dementia as the deficiency grows more severe.