Evaluation of the Effects of Calcitriol's in the Neurological Symptoms of Friedreich's Ataxia Patients

Inclusion Criteria: * Patients with Friedreich's Ataxia and confirmed genetic diagnosis with: * Two pathological GAA triplet repeats in the gen FXN * One pathological GAA triplet repeat and one point mutation in the gen FXN * Patients between 16 and 65 years of age. * To keep the walking ability, although an external aid is needed. * Women with confirmed genetic diagnosis must use an effective contraceptive method during the trial. Exclusion Criteria: * Any neurological or other kind of disease that could interfere in the trial according to the investigator judgement. * Severe visual loss. * Severe auditory loss. * Cognitive decline\*. * Dementia or affective-cognitive cerebellar syndrome. * Serious psychiatric illness during the six previous months of the trial inclusion. * Substance abuse during the six previous months of the trial inclusion. * Severe drug allergy. * Cardiac disease: * Ejection fraction \<40% \[N: 50-70%\] * Heart failure \> 2 from NYHA (New York Heart Association) criteria. * Significant valvular heart disease. * Symptomatic coronary artery disease. * Cardiac arrhythmia with hemodynamic compromise (atrial fibrillation). * Prolonged immobilisation * Use of research drugs during the 30 previous days of the trial inclusion. * Concomitant treatment with digoxin, thiazide diuretics, cholestyramine, corticoids, laxatives with magnesium, barbiturates and antiepileptic drugs. Use of Calcium or Vitamin D drugs during the 30 previous days of th…