Nutritional supplements that may be helpful: Vitamin E has been found in a number of studies to reduce the severity of TD. In a double-blind trial, people with TD were randomly assigned to receive vitamin E (800 IU per day for two weeks and 1,600 IU per day thereafter) or a placebo. Vitamin E was significantly more effective than placebo in reducing involuntary movements.¹ An uncontrolled study of 20 people with TD reported that 1,600 IU of vitamin E per day may be the optimal amount;² this large amount should be supervised by a healthcare practitioner. Other studies have also found that vitamin E supplements reduce the severity of TD.^{3 4 5} Two studies failed to show a beneficial effect of vitamin E.^{6 7} However, the people in those studies had been receiving neuroleptics for at least ten years, and research has shown that vitamin E is most effective when started within the first five years of neuroleptic treatment.^{8 9}

Choline and lecithin have both been used for people with TD. While some studies have shown a beneficial effect,^{10 11 12} others have reported variable improvement¹³ or no improvement.¹⁴ In a small, two-week, double-blind trial, people with TD were given 25 grams of lecithin twice a day, or a matching placebo. All participants experienced significant improvement of symptoms.¹⁵

Dimethylaminoethanol (DMAE) is a natural choline precursor. Although some preliminary data suggested that DMAE could decrease TD symptoms,¹⁶ most studies show that DMAE is no more effective than placebo for TD.¹⁷

One doctor has found that administering the trace mineral manganese (15 mg per day) can prevent the development of TD and that higher amounts (up to 60 mg per day) can reverse TD that has already developed.¹⁸ Other researchers have reported similar improvements with manganese.^{19 20}

Several people have experienced an improvement in TD while taking evening primrose oil (EPO).²¹ In a double-blind study, however, supplementing with EPO (12 capsules per day) resulted only in a minor, clinically insignificant improvement.²²

Preliminary research has linked TD to the inability of the body to metabolize the amino acidphenylalanine. Supplementing with branched-chain amino acids (BCAA), including valine, isoleucine, and leucine, could reduce excess phenylalanine in people with this disorder. In one trial, researchers examined the effects of BCAA supplementation in people with TD (from 150 mg per 2.2 pounds body weight, up to 209 mg per 2.2 pounds body weight) after breakfast and one hour before lunch and dinner for two weeks.²³ The BCAA mixture included equal parts valine and isoleucine plus 33% more leucine than either of the other two amino acids. Of nine people treated, six experienced at least a 58% reduction in symptoms, and all nine had a least a 38% decrease.

During a ten-year period, doctors at the North Nassau Mental Health Center in New York treated approximately 11,000 schizophrenics with a megavitamin regimen that included vitamin C (up to 4 grams per day), vitamin B3—either as niacin or niacinamide—(up to 4 grams per day), vitamin B6 (up to 800 mg per day), and vitamin E (up to 1,200 IU per day). During that time, not a single new case of TD was seen, even though many of the people were taking neuroleptic drugs.²⁴ Another psychiatrist who routinely used niacinamide, vitamin C, and vitamin B-complex over a 28-year period rarely saw TD develop in her patients.²⁵ Further research is needed to determine which nutrients or combinations of nutrients were most important for preventing TD. The amounts of niacinamide and vitamin B6 used in this research may cause significant side effects and may require monitoring by a doctor.