RESUMO
BACKGROUND: Vitamin B12 and folic acid deficiency are common in the older and are associated with several conditions including anaemia, cardiovascular disease, cognitive impairment and cancer. Evidence from in vitro studies suggests that solar radiation can degrade both vitamins in the skin. Chile is the longest country in the world running perfectly North-South making it an ideal place to study potential associations of latitude and solar radiation on vitamin B12 and folic acid deficiency. OBJECTIVES: The objective was to examine the association between vitamin B12 and folic acid deficiencies and latitude. METHODS: Plasma samples were collected from Chileans aged 65+ years (n=1013) living across the whole country and assayed for vitamin B12 and folic acid concentrations as part of the Chilean Health Survey 2009-2010, which is a national representative sample study. RESULTS: Overall, the prevalence of vitamin B12 deficiency was 11.3%, with the prevalence in the North of the country being significantly greater than in the Central and South zones (19.1%,10.5%, and 5.7%, respectively; P<0.001). The prevalence of folic acid deficiency in the whole cohort was 0.7% with no difference between the 3 geographical zones. Using logistic regression analyses, vitamin B12 deficiency was significantly associated with geographical latitude (OR 0.910 [95% confidence intervals 0.890-0.940], P<0.001) and solar radiation (OR 1.203 [95% confidence intervals 1.119-1.294], P<<0.001). These associations persisted after adjustments for confounders (OR 0.930, P<0.001 and 1.198, P=0.002, respectively). CONCLUSIONS: In the Chilean population of 65+, the prevalence of vitamin B12 deficiency is associated with living closer to the Equator and solar radiation. Although degradation by solar radiation might explain this observation, further work is required to establish the potential mechanisms. In countries that routinely fortify food with folic acid, efforts to identify vitamin B12 deficiency might be more cost-efficiently targeted in areas closest to the Equator.
Assuntos
Deficiência de Vitamina B 12/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Chile , Estudos de Coortes , Demografia , Ensaio de Imunoadsorção Enzimática , Feminino , Ácido Fólico/sangue , Deficiência de Ácido Fólico/epidemiologia , Deficiência de Ácido Fólico/patologia , Humanos , Luz , Modelos Logísticos , Masculino , Prevalência , Pele/efeitos da radiação , Vitamina B 12/sangue , Deficiência de Vitamina B 12/patologiaAssuntos
Anemia Megaloblástica/complicações , Síndrome do Intestino Irritável/complicações , Doenças da Boca/diagnóstico , Anemia Megaloblástica/etiologia , Anemia Megaloblástica/patologia , Diagnóstico Diferencial , Humanos , Síndrome do Intestino Irritável/patologia , Masculino , Pessoa de Meia-Idade , Doenças da Boca/etiologia , Doenças da Boca/patologia , Mucosa Bucal/patologia , Língua/patologia , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/etiologia , Deficiência de Vitamina B 12/patologiaRESUMO
BACKGROUND: Subacute combined degeneration is a clinical manifestation of vitamin B12 deficiency, that we observe with unusual frequency. AIM: To report a series of eleven patients with subacute combined degeneration. PATIENTS AND METHODS: Retrospective analysis of 11 patients hospitalized in a public hospital in Santiago, between March 2001 and February 2003. All had a myelopathy of more than three weeks of evolution with serum vitamin B12 levels of less than 200 pg/ml. RESULTS: A risk factor was identified in 10 cases and the most common was an age over 60 years old. The main presenting symptom was the presence of paresthesias. On admission, sphincter dysfunction, posterior column and pyramidal syndromes coexisted in nine patients. A level of sensitive deficit was detected in six. Ten patients had macrocytosis and eight were anemic. Serum vitamin B12 was measured in ten and in nine, it was below 200 pg/ml. The mean lapse between onset of symptoms and treatment was eight months. All received intramuscular vitamin B12 in doses on 1,000 to 10,000 IU/day. Sphincter dysfunction and propioception were the first symptoms to improve. CONCLUSIONS: Subacute combined degeneration must be suspected in patients older than 60 years with a subacute myelopathic syndrome and low serum vitamin B12 levels.
Assuntos
Degeneração Neural/etiologia , Doenças da Medula Espinal/etiologia , Medula Espinal/patologia , Deficiência de Vitamina B 12/complicações , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Degeneração Neural/patologia , Parestesia/etiologia , Estudos Retrospectivos , Doenças da Medula Espinal/patologia , Deficiência de Vitamina B 12/patologiaRESUMO
We carried out this work with the purpose of studying the effects of protein and vitamin B deficiency on the morphologic and quantitative aspects of the myenteric plexus of the descending colon of adult Rattus norvegicus. Twenty-eight rats were divided in two groups, one of them receiving chow with 22% protein level (control) and the other fed with chow having 8% protein level without vitamin B supplementation, during 120 days. Whole-mounts of the descending colon were prepared and stained with Giemsa, NADH-diaphorase and NADPH-diaphorase. The undernourished rats had a body weight 11.84% less than the control group. Relative to the controls, the experimental group had a colonic area 48% smaller, 51.9% less Giemsa-stained neurons, 28.3% less NADH-diaphorase positive neurons and 24.2% less NADPH-diaphorase positive neurons.