Use of vitamins by participants in amyotrophic lateral sclerosis clinical trials

Patients' vitamin intake is often not documented and is therefore not considered sufficiently in studies of prescribed medication in patients with amyotrophic lateral sclerosis (ALS). We aimed to determine the prevalence of vitamin use by participants in ALS clinical trials. Data about demographics, disease severity (ALS Functional Rating Scale) and concomitant medication were obtained from the Pooled Resource Open-Access ALS Clinical Trials Database, which contains records from more than 6000 ALS patients who participated in 23 phase II/III clinical trials. Information about vitamin intake for all study subjects was coded into major categories. Clinical data of vitamin users and nonusers were compared, and regression analysis was used to explore the associations among clinical parameters, vitamin use and two measures of disease progression. From the 40.996 available medication records from 6274 subjects, 7338 (17.9%) concerned vitamins. One or more vitamins were used by 3331 subjects (53.1%). Most common was vitamin E, vitamin C and multivitamins. Patients who did and did not take vitamins did not differ in terms of disease progression and ALS Functional Rating Scale score. Patients who took vitamins were younger, were more often female, had a shorter time between onset and diagnosis, had shorter disease duration and more frequently had limb-onset types. Disease progression rate and disease aggressiveness were not associated with vitamin use. Despite unclear evidence, the use of vitamins in ALS is common. However, rapid progression was not observed to be associated with vitamin use.