Dear Doc: Is Vitamin B12 back in vogue?
Vail CO, Colorado
I began my medical practice on July 1, 1990. I was the “new” doc in town, having taken over the practice of a retiring physician. He had a receptionist who took care of everything, including giving a multitude of allergy and B12 shots. It seemed everyone received B12 shots. They were the cure for any ailment, affliction, malady and perhaps even true B12 deficiency. I thought I knew better, that it was just a placebo effect, but those patients sure believed that B12 shot made them better. As time moved forward ubiquitous B12 injections fell out of vogue. Recently however, B12 has really been making news. Are we going back to the “good old days”?
I’ve been tired and dizzy lately. I have a healthy diet and try to exercise when I can. I was told I should get my B12 level checked because I might be deficient. What does that mean?
Tired in Eagle
There seems to be a lot of that going around. In fact fatigue is one of the most common medical complaints and the cause can range from a lack of sleep, to anemia, diabetes, stress and a host of other medical problems. Vitamin B12 deficiency may be a cause as well.
Vitamin B12, also called cobalamin, has gathered a lot of press recently. While it has been long recognized as a cause of anemia, recent attention has focused on its heart and neurologic benefits. Symptoms of B12 deficiency fall into a wide range, including:
– Low white blood cell counts and low platelets
– Numbness and tingling of the extremities
– Peripheral neuropathy
– Personality changes
– Memory loss from mild to dementia
– Possible increased risk of myocardial infarction and stroke
A recent, but small study from the University of Oxford in England suggested that higher levels of Vitamin B12 in otherwise healthy adults over 61 years of age decreased the risk of brain atrophy or shrinkage, a process normally associated with aging. While the exact implications of this finding are unclear, it poses intriguing questions on our aging brains and the effect Vitamin B12 may have on them. B12 deficiency has also been associated with numerous neurological and psychiatric conditions, although the exact reason for this relationship remains unclear. It seems to have broad benefits to our brains, spinal cord and peripheral nerves, as well as stabilizing our mood and sense of well being.
The heart benefits of vitamin B12 is also earning a lot of recent attention, and the reasons are becoming better understood. Like folic acid, B12 acts as a cofactor in converting homocysteine to methionine. Low levels of vitamin B12 then can lead to elevated homocysteine levels. Elevated homocysteine levels are recognized as an independent risk factor for atherosclerotic cardiovascular disease, or hardening of the arteries.
Despite all the recent attention, it is not known how common B12 deficiency is. Some researchers have estimated that as many as 15 percent of people over the age of 65 are low in vitamin B12. At the same time, a simple blood test of your B12 may not be accurate enough to predict whether you are actually deficient. The range of normal vitamin B12 levels is quite large, so measured levels at the lower end of the normal range may still cause symptoms in sensitive individuals. Vitamin B12 levels below 200 pg/ml are clearly deficient, while levels above 400 pg/ml are considered normal. The use of methylmalonic acid and homocysteine levels can be very helpful in confirming the diagnosis in individuals with B12 levels between 200 pg/ml and 400 pg/ml. If both of these are normal, vitamin B12 deficiency is ruled out; if either is abnormally elevated then B12 deficiency is confirmed.
While the average American diet should contain plenty of Vitamin B12, there are many reasons someone can become deficient. Do not assume that because you eat healthy your B12 levels are normal. In my next article, I will talk about diseases and conditions that cause vitamin B12 deficiency as well as how it is treated, so stay tuned!
Let me know what’s on your mind at firstname.lastname@example.org. Remember your health is your responsibility! Health is our greatest asset and it doesn’t happen by accident. If something doesn’t seem right, or questions are left unanswered don’t wait, call your doctor.
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