Effect of fat on serum 25-hydroxyvitamin D levels after a single oral dose of vitamin D in young healthy adults: a double-blind randomized placebo-controlled study.

PURPOSE: This double-blind placebo-controlled trial evaluated serum 25-hydroxyvitamin D [25(OH)D] levels after the oral intake of a single dose of cholecalciferol during one of the three meals, containing different amounts of fat or placebo. METHODS AND RESULTS: Sixty-four healthy medical residents or students of a university hospital in Porto Alegre, latitude 30° S, Brazil, were divided into four groups. Three groups received a single 50,000 IU oral dose of cholecalciferol during a meal containing 0 g (Group 1), 15 g (Group 2) or 30 g (Group 3) of fat, and one group received placebo (Group 4), according to randomization. Serum 25(OH)D, parathyroid hormone, total calcium, albumin, magnesium, and creatinine levels, and urinary calcium, magnesium, and creatinine levels were measured at baseline and after 14 days. Baseline mean serum 25(OH)D levels were low in all groups. Vitamin D given during breakfast increased the mean change of serum 25(OH)D levels, when compared to placebo. Furthermore, the intake of fat with vitamin D increased the mean change of serum 25(OH)D levels. CONCLUSION: A single oral dose of vitamin D given with food increased mean serum 25(OH)D levels, after 2 weeks, and the mean increase was larger, when the meal had at least 15 g of fat. These findings can have important implications to oral vitamin D supplementation.

Prevalence of low bone mineral density in adolescents and adults with cystic fibrosis.

OBJECTIVE: The aim of this cross-sectional study was to evaluate the prevalence of low bone mass density in cystic fibrosis patients as well as to evaluate the factors associated with bone mass in such patients. METHODS: Bone mass density was measured by dual-photon X-ray absorptiometry of lumbar spine (L1-L4), in patients ≤19 years old, or lumbar spine and femur (total and neck) in patients ≥20 years old. Evaluations of nutritional status, biochemical parameters, and lung function were performed. Medication data were obtained from medical records. RESULTS: Fifty-eight patients were included in the study (25 males/ 33 females), mean age 23.9 years (16-53 years). The prevalence of bone mass below the expected range for age at any site was 20.7%. None of the subjects had history of fracture. Lumbar spine Z-score in cystic fibrosis patients correlated positively with body mass index (r= 0.3, p=0.001), and forced expiratory volume in the first second (% predicted) (r=0.415, p=0.022). Mean lumbar spine Z-score was higher in women (p=0.001), in patients with no pancreatic insufficiency (p=0.032), and in patients with no hospitalization in the last 3 months (p=0.02). After multivariate analysis, body mass index (p= 0.001) and sex (p=0.001) were independently associated with Z-score in lumbar spine. CONCLUSION: Low bone mass is a frequent problem in patients with CF, being independently associated with body mass index, and male sex.

Prevalence of low bone mineral density in adolescents and adults with cystic fibrosis / Prevalência de densidade mineral óssea baixa em adolescentes e adultos com fibrose cística

Objective The aim of this cross-sectional study was to evaluate the prevalence of low bone mass density in cystic fibrosis patients as well as to evaluate the factors associated with bone mass in such patients. Methods Bone mass density was measured by dual-photon X-ray absorptiometry of lumbar spine (L1-L4), in patients ≤19 years old, or lumbar spine and femur (total and neck) in patients ≥20 years old. Evaluations of nutritional status, biochemical parameters, and lung function were performed. Medication data were obtained from medical records. Results Fifty-eight patients were included in the study (25 males/ 33 females), mean age 23.9 years (16-53years). The prevalence of bone mass below the expected range for age at any site was 20.7%. None of the subjects had history of fracture. Lumbar spine Z-score in cystic fibrosis patients correlated positively with body mass index (r= 0.3, p=0.001), and forced expiratory volume in the first second (% predicted) (r=0.415, p=0.022). Mean lumbar spine Z-score was higher in women (p=0.001), in patients with no pancreatic insufficiency (p=0.032), and in patients with no hospitalization in the last 3 months (p=0.02). After multivariate analysis, body mass index (p= 0.001) and sex (p=0.001) were independently associated with Z-score in lumbar spine. Conclusion Low bone mass is a frequent problem in patients with CF, being independently associated with body mass index, and male sex. .

Objetivo Determinar a prevalência de massa óssea baixa em pacientes adolescentes e adultos com fibrose cística e estudar os fatores potencialmente associados. Métodos Densidade mineral óssea foi determinada por absorciometria por dupla emissão de raios X na coluna lombar em pacientes ≤ 19 anos e na coluna e no fêmur em pacientes ≥ 20 anos. Avaliações nutricionais, bioquímicas e pulmonares foram realizadas. Dados referentes ao tratamento farmacológico foram coletados. Resultados 58 pacientes foram incluídos no estudo (25 homens/33 mulheres), média de idade de 23,9 anos (16-53). Massa óssea abaixo da esperada foi verificada em 20,7% dos pacientes. Não houve histórico de fratura. Z-score da coluna lombar associou-se positivamente com índice de massa corporal (r=0,3; p=0,022), volume expiratório forçado (% previsto) (r=0,415; p=0,001). A média do Z-score da coluna foi mais alta nas mulheres que nos homens (p=0,001), em pacientes que não possuíam insuficiência pancreática (p=0,02) e em pacientes que não haviam sido hospitalizados nos últimos três meses (p=0,032). Os fatores encontrados como preditores independentes de Z-score da coluna lombar foram sexo masculino (p=0,001) e índice de massa corporal (p=0,001). Conclusão Massa óssea baixa é frequente em pacientes com FC, estando associada independentemente com índice de massa corporal e sexo masculino. .

Hypovitaminosis D in patients with cystic fibrosis: a cross-section study in South Brazil.

INTRODUCTION: Cystic fibrosis (CF) patients have a susceptibility to vitamin D deficiency because of nutrient malabsorption. OBJECTIVES: To evaluate the prevalence of hypovitaminosis D in CF patients and the factors associated with serum 25-hydroxyvitamin D levels. METHODS: We evaluated the prevalence of vitamin D deficiency defined as 25-hydroxyvitamin D <30 ng/mL, as suggested recently by the Cystic Fibrosis Foundation, and factors associated with its serum levels. Patients with confirmed CF were included. Nutritional status and hospital admissions were evaluated. Serum C-reactive protein, calcium, phosphate, magnesium, albumin, 25-hydroxyvitamin D and parathyroid hormone levels were measured. Lung function was evaluated by spirometry, and clinical and chest radiographic scores were assessed. Statistical significance level was set at P < 0.05. RESULTS: Fifty-nine patients were included. Prevalence of hypovitaminosis D was 61%. Patients with pancreatic insufficiency had a trend to have higher vitamin D levels. Sixteen patients had severe lung disease with percentage of forced expiratory volume in 1 s predicted below 40%. After multivariate analysis, body mass index and hospitalization in the last month remained significantly associated with serum vitamin D levels. CONCLUSIONS: Vitamin D insufficiency is still a problem in CF patients, even in those receiving supplementation.