RESUMEN
La vitamina D (VD) y sus acciones en el ser humano son objeto de una activa investigación en años recientes, ligada a la descripción de nuevos roles metabólicos, además de su conocida participación en el metabolismo del calcio y del hueso. En niños, algunas enfermedades neurológicas crónicas, como la parálisis cerebral, presentan un riesgo aumentado de deficiencia de VD, explicándose por una ingesta deficiente de ella, una menor exposición solar, requerimiento asociado al proceso de crecimiento, enfermedades intercurrentes y al uso frecuente de drogas antiepilépticas. En esta revisión se analizan los factores asociados a la deficiencia de VD y se plantea la necesidad de evaluar sistemáticamente el estado nutricional de esta vitamina en pacientes con enfermedades neurológicas de riesgo, sus posibles efectos metabólicos, implicancias clínicas y la necesidad de usar alimentos fortificados o suplementación con VD.
Vitamin D (VD) has been object of an active research in the last years, especially in relation with the findings of its new roles, besides its well known participation in calcium and bone metabolism. In children, some chronic neurologic diseases, like cerebral palsy, show an increased risk of VD deficiency, which could be explained by low intake, reduced sun exposure, requirements associated to growth process, intercurrent diseases and frequent use of antiepileptic drugs. In this review, factors associated to VD deficiency are analyzed, pointing to the need of a systematic assessment of the VD nutritional status in patients with neurological diseases associated to this deficiency, its possible metabolic effects, clinical implications and the need of fortified foods or VD supplementation.
Asunto(s)
Humanos , Anticonvulsivantes/efectos adversos , Deficiencia de Vitamina D/etiología , Parálisis Cerebral/complicaciones , Deficiencia de Vitamina D/inducido químicamente , Deficiencia de Vitamina D/prevención & control , Enfermedades del Sistema Nervioso , Factores de Riesgo , Necesidades Nutricionales , Parálisis Cerebral/tratamiento farmacológico , Vitamina D/metabolismo , Vitamina D/uso terapéutico , Ácido Valproico/efectos adversosRESUMEN
A hydroponic experiment was carried out to determine the root exudation patterns in two Cu-metallophytes (Oenothera picensis and Imperata condensata) and two agricultural plants (Lupinus albus and Helianthus annuus). Plants were grown in nutrient solution at increasing Cu doses (0, 0.125, 0.25, 0.5, 1 and 2mgCuL(-1)), and plant growth, root elongation, Cu accumulation and root exudates were measured. All plants showed a decrease of over 60% in root elongation at the highest Cu supply level, being O. picensis the most sensitive specie and showing the highest shoot and root Cu concentrations (116 and 2657µgCug(-1), respectively), which were six fold higher than the other species. Differences in root exudation patterns of low molecular weight organic acids were found, with extremely high amounts of succinic acid exuded by O. picensis (1049µmolg(-1)h(-1)), and citric acid by I. condensata (164µmolg(-1)h(-1)). In metallophytes, the organic acid exudation was increased even with no root elongation, meanwhile agricultural plants exuded citric acid at constant levels. Exudation of phenolic compounds was highly species-dependent, with catechin mainly exuded by I. condensata, (2.62µmolg(-1)h(-1)) cinnamic acid by O. picensis (5.08µmolg(-1)h(-1)) and coumaric acid exclusively exuded by H. annuus (13.6µmolg(-1)h(-1)) at high Cu levels. These results indicated that differences in root exudation patterns among metallophytes and agricultural plants could affect their Cu tolerance. Particularly, the higher exudation rate showed by I. condensata can be an effective exclusion mechanism to tolerate high Cu concentrations, supporting its use in Cu phytostabilization programs.