Psychiatric interest in folic acid has developed over the past three years. Small amounts are added to flour in order to prevent the development of spina bifida in babies. People with depression tend to be low in folic acid, and when taken in large doses of 25 milligrams per day and above, it has anti depressant properties. The fear that it will mask pernicious anemia is unjustified but pervasive, and it is the reason why the five milligram tablets are available only on prescription. Over the counter 1 milligram pills are available. Any of the current B-complex preparations will provide enough B-12 to assure anyone that pernicious anemia will not develop.
Hunter, in reviewing the need to add folic acid to flour to prevent spina bifida wrote, “Concerns about vitamin B12 originate from findings in the late 1940s that while pernicious anemia responded well to folate, the neurological signs of B12 deficiency neither responded nor were prevented”. Indeed, it became part of medical dogma that folate could precipitate more severe and aggressive neurological complications. Dickinson did a comparison of case studies and series of patients with B12 deficiency, before and after the introduction of treatment with folic acid, and found no evidence that folate increased the rate or the severity of the neurological presentation of B12 deficiency. About 28 per cent of cases of B12 deficiency present neurologically, and practicing physicians should always consider this diagnosis in a patient with paresthesia, weakness, or ataxia. Dickinson considered it absurd to withhold supplements because some patients with pernicious anemia might not be sick enough to be diagnosed by their physician.”