Oral supplements of vitamin B12 appear to correct vitamin B12 deficiencies as well as B12 injections, according to study findings released Monday.

However, the group of European researchers found that, in order to correct a deficiency, oral doses need to contain more than 200 times the recommended daily allowance (RDA) of Vitamin B12.

Study author Dr. Lisette C. P. G. M. de Groot of Wageningen University in the Netherlands explained that most people develop vitamin B12 deficiencies as a result of “malabsorption,” in which their bodies become unable to extract vitamin B12 from food.

The deficiency typically strikes older people, she added, and takes years to develop. In some instances, people who avoid animal products - such as vegans and followers of a macrobiotic diet - can also develop a deficiency in vitamin B12 as a result of not eating enough B12-rich foods, de Groot noted.

A vitamin B12 deficiency is typically treated by monthly, often painful, shots, de Groot and her colleagues, including Simone J. P. M. Eussen, report in the Archives of Internal Medicine.

To investigate whether an oral dose of Vitamin B12 works, as well, they tested various daily doses of oral vitamin B12 supplements in 120 people aged 70 and older.

They found that daily oral doses of 647 to 1032 micrograms of vitamin B12 appeared to correct the deficiency. The current RDA for vitamin B12 is 3 micrograms per day.

Despite the massive doses needed, oral medicine has the advantage of being easy to administer and painless, said de Groot. No side effects have been reported, she added.

SOURCE: Archives of Internal Medicine, May 23, 2005.