Q: I’ve been feeling tired so my doctor did a physical and some blood tests. Apparently, I am anemic because I’m low in Vitamin B12. What could cause this, and what is the treatment? I am a vegetarian, but I have been eating a healthy, well balanced diet for years.
A: You can actually be Vitamin B12 deficient for years before developing any symptoms such as feeling tired, weak or dizzy.
If you don’t have enough Vitamin B12, your blood tests may show enlarged, abnormal appearing red blood cells, but the only way to prove a deficiency is if you have a low Vitamin B12 level. There are other tests that are suggestive of Vitamin B12 deficiency such as an elevated methylmalonic acid or homocysteine level.
In some cases, testing may include LDH, bilirubin, iron, and folate levels, or an upper gastrointestinal endoscopy. A bone marrow biopsy may be considered if the symptoms are serious and the diagnosis is unclear.
There are multiple causes of Vitamin B12 deficiency, and your likelihood of developing it increases with age.
A B12 deficiency is relatively common. Many people over 50 are mildly deficient, but 3% have more serious Vitamin B12 deficiencies.
Because it cannot be made by the body, you must ingest and absorb adequate amounts of B12. The average adult needs 2.4 micrograms per day.
Plants do not produce Vitamin B12, so you either have to ingest it from animal sources, yeast extracts, fortified cereals, or from B12 supplementation. Some vegetarians don't eat enough eggs and dairy products so they gradually develop a B12 deficiency if they’re not supplementing. This is even more of an issue for vegans, so ask your doctor to test you intermittently and advise if B12 supplementation is necessary.
Even if you are ingesting enough Vitamin B12, its possible you’re not absorbing it adequately.
Did you know that excessive alcohol intake interferes with absorption? So does long term use of metformin (for blood sugar) or proton pump inhibitors (like omeprazole or lansoprazole) taken to reduce stomach acid.
Some other causes of poor absorption include weight loss surgery, partial removal of the stomach or intestine, inflammatory bowel diseases, or parasites.
Intrinsic factor produced in your stomach helps the body absorb Vitamin B12. If you don’t have enough intrinsic factor in your stomach (often associated with atrophic gastritis, or thinning of the stomach lining), you can develop a serious form of B12 deficiency called pernicious anemia. Pernicious anemia may be associated with other autoimmune diseases such as hypothyroidism or lupus.
Symptoms in severe cases of Vitamin B12 deficiency may include shortness of breath, rapid heartbeats, diarrhea or constipation, nausea, poor appetite, weight loss, a beefy red, sore tongue, or even neurological damage. Neurologic symptoms range from poor concentration to depression, irritability, gait problems, loss of balance, neuropathy in hands and feet, or even psychosis or dementia in extreme cases.
Sometimes the neurological symptoms are irreversible, so it is important to treat Vitamin B12 deficiency.
Treatment starts with improving your diet and replenishing the B12 levels in your body.
Vitamin B12 may be taken orally or by injection. For more severe deficiencies, B12 may be loaded in your body with higher doses initially (i.e. a shot once per week, or higher dose pills daily) until your level is restored.
Sublingual, oral, nasal or injectable forms of B12 are equally effective in most patients, although much higher oral doses may be required if malabsorption is the cause of the B12 deficiency.
Make sure to get enough dietary folic acid and vitamin C, too, but don’t take Vitamin C at the same time as B12.
Ask your doctor about any other drug interactions, and about treating underlying absorption problems.