Bone disease in vitamin D-deficient patients with Crohn's disease

Vitamin D deficiency is frequently observed in patients with Crohn's disease and may be associated with an increased risk of development of metabolic bone disease. To estimate the incidence of metabolic bone disease by noninvasive methods, 31 patients (17–75 years old) with Crohn's disease and low 25-hydroxy vitamin D (25-OHD) levels in winter were investigated in the following summer by measuring the bone mineral content (BMC) of the distal radius by single photon absorptiometry and the cortical area ratio (CAR) calculated from radiographs of the right hand and by x-ray of the lumbar spine. Forty-five percent of the patients showed signs of metabolic bone disease. BMC and CAR correlated with 25-OHD serum levels (P<0.05), especially in men. Furthermore, the amount of sun exposure has an influence not only on 25-OHD serum levels both in summer and in winter (P=0.0006), but also on the BMC (P=0.07). Consequently, vitamin D deficiency is of major importance for the development of metabolic bone disease in patients with Crohn's disease. Vitamin D deficiency can be prevented by increasing sun exposure and long-term vitamin D supplementation.     

Serum vitamin D levels in children with cystic fibrosis

Osteopenia is increasingly recognized in adults with cystic fibrosis (CF), and is potentially related to vitamin D deficiency in both adulthood and childhood. Vitamin D supplements are recommended and prescribed to all pancreatic-insufficient patients. We aimed to ascertain whether vitamin D deficiency in children with CF was prevalent. 25-hydroxyvitamin D (25-OHD) was measured in 290 children attending a specialist pediatric CF clinic for annual assessment. 25-OHD levels were compared with reference values and to other biochemical markers, lung function, and growth. Levels were also analyzed by pancreatic status and by the presence of CF-related liver disease. Median 25-OHD was 65 (range, 9-190) nmol/l. One percent had levels below 15 nmol/l, and 6% had levels less than 25 nmol/l. Levels were lower in adolescents (P < 0.001) and during the "winter" months (P < 0.001). No relationship was found with pancreatic status or liver disease. In conclusion, the majority of children had normal 25-OHD levels. Interpretation is difficult due to a lack of knowledge of optimal levels of 25-OHD required for healthy bone accretion. Lower levels in adolescents may be a precursor to low levels in adulthood, and did not seem to be simply related to poor compliance with supplementation. This may reflect normal physiology.     

Low serum and bone vitamin K status in patients with longstanding Crohn's disease: another pathogenetic factor of osteoporosis in Crohn's disease?

BACKGROUND: A high prevalence of osteoporosis is reported in Crohn's disease. The pathogenesis is not completely understood but is probably multifactorial. Longstanding Crohn's disease is associated with a deficiency of fat soluble vitamins, among them vitamin K. Vitamin K is a cofactor in the carboxylation of osteocalcin, a protein essential for calcium binding to bone. A high level of circulating uncarboxylated osteocalcin is a sensitive marker of vitamin K deficiency. AIMS: To determine serum and bone vitamin K status in patients with Crohn's disease and to elucidate its relationship with bone mineral density. METHODS: Bone mineral density was measured in 32 patients with longstanding Crohn's disease and small bowel involvement, currently in remission, and receiving less than 5 mg of prednisolone daily. Serum levels of vitamins D and K, triglycerides, and total immunoreactive osteocalcin, as well as uncarboxylated osteocalcin ("free" osteocalcin) were determined. The hydroxyapatite binding capacity of osteocalcin was calculated. Data were compared with an age and sex matched control population. RESULTS: Serum vitamin K levels of CD patients were significantly decreased compared with normal controls (p<0.01). "Free" osteocalcin was higher and hydroxyapatite binding capacity of circulating osteocalcin was lower than in matched controls (p<0.05 and p<0.001, respectively), indicating a low bone vitamin K status in Crohn's disease. In patients, an inverse correlation was found between "free" osteocalcin and lumbar spine bone mineral density (r=-0.375, p<0.05) and between "free" osteocalcin and the z score of the lumbar spine (r=-0.381, p<0.05). Multiple linear regression analysis showed that "free" osteocalcin was an independent risk factor for low bone mineral density of the lumbar spine whereas serum vitamin D was not. CONCLUSIONS: The finding that a poor vitamin K status is associated with low bone mineral density in longstanding Crohn's disease may have implications for the prevention and treatment of osteoporosis in this disorder.     

Vitamin D status as a determinant of peak bone mass in young Finnish men

Severe vitamin D deficiency causes rickets, but scarce data are available about the extent to which vitamin D status determines the development of the peak bone mass in young adults. Our aim was to evaluate the prevalence of vitamin D deficiency [serum 25-hydroxyvitamin D (25-OHD) less than the lower limit of the reference range of 20-105 nmol/liter] and the relationship between vitamin D status and peak bone mass among young Finnish men. A cross-sectional study of determinants of peak bone mass with data on lifestyle factors collected retrospectively was performed in 220 young men, aged 18.3-20.6 yr. One hundred and seventy men were recruits of the Finnish Army, and 50 were men of similar age who had postponed their military service for reasons not related to health. Bone mineral content, bone mineral density, and scan area were measured in lumbar spine and upper femur by dual energy x-ray absorptiometry. Serum 25-OHD concentrations were followed prospectively for 1 yr. In July 2000, only 0.9% of the men had vitamin D deficiency, but 6 months later, in the winter, the respective percentage was 38.9%. After adjusting for age, height, weight, exercise, smoking, calcium, and alcohol intake, there existed a positive correlation between serum 25-OHD and bone mineral content at lumbar spine (P = 0.057), femoral neck (P = 0.041), trochanter (P = 0.010), and total hip (P = 0.025). The correlation coefficients for the bone mineral densities at the four measurement sites were 0.035, 0.061, 0.056, and 0.068, respectively. No correlation was found to scan area. We conclude that vitamin D deficiency is very common in Finnish young men in the winter, and it may have detrimental effects on the acquisition of maximal peak bone mass. As in Finland vitamin D supplementation to infants is now stopped at the age of 3 yr, it can be asked whether at our latitude it should be continued from that age onward, not for the prevention of rickets, but as prophylaxis for osteoporosis.     

Vitamin D deficiency in Crohn's disease: Prevalence,risk factors and supplement use in an outpatient setting

Background and aimsVitamin D deficiency impacts on bone health and has potential new roles in inflammation. We aimed to determine the prevalence of and risk factors for vitamin D deficiency and to explore vitamin D supplement usage in patients with Crohn's disease (CD) in an outpatient setting, compared with controls.MethodsSerum 25-hydroxyvitamin D [25(OH)D] concentrations were measured by radioimmunoassay in 151 participants, comprising 81 CD patients and 70 age-, sex- and socio-economic status-matched healthy controls. Levels of 25(OH)D < 50 nmol/L were classed as deficient. Data on vitamin supplement usage were recorded for all participants at interview.ResultsVitamin D deficiency was common in patients with CD (63%) and significantly higher in winter than summer (68% v 50%; p < 0.001, χ²). Notably, the deficiency rate remained high even in summer (50%). On regression analysis, 25(OH)D levels were inversely associated with winter season. Disease-specific factors for lower serum 25(OH)D levels were longer disease duration and smoking. Overall, 43% of patients reported using a vitamin D-containing supplement, primarily at low dosages (200–400 IU/d); however, this level of supplement did not prevent deficiency. For the majority of CD patients, 25(OH)D remained below optimal levels proposed to confer bone and immune health benefits.ConclusionsVitamin D deficiency was common in patients with CD and associated with longstanding disease, smoking and winter. While over 40% of patients used a vitamin D-containing supplement, the dosages were inadequate to prevent deficiency. Appropriate vitamin D screening and supplementation should be considered in the context of health promotion of outpatients with CD.     

Vitamin D status and measurements of markers of bone metabolism in patients with small intestinal resection

BACKGROUND AND AIMS: Vitamin D deficiency is common in patients with small intestinal resection and may lead to secondary hypersecretion of parathyroid hormone (PTH), which in turn may result in increased bone turnover rate and loss of bone mineral. The aims of this study were to investigate the prevalence of vitamin D deficiency, as assessed by low serum concentrations of 25-hydroxyvitamin D (25(OH)D) in patients with small intestinal resection and to explore the relation of 25(OH)D to PTH, markers of bone turnover rate, and bone mineral density (BMD) in these patients. PATIENTS: Forty two patients with small intestinal resection, a faecal energy excretion of more than 2.0 MJ/day, and a mean length of the remaining small intestine of 199 cm were included. Diagnoses were Crohn's disease (n=35) and other (n=7). METHODS: 25(OH)D was analysed by radioimmunoassay and bone turnover rate was assessed by measurement of serum osteocalcin, serum alkaline phosphatase, urine pyridinoline, and urine deoxypyridinoline. BMD was measured by dual energy x ray absorptiometry. RESULTS: Mean 25(OH)D concentration was 13.4 (SD 9.7) ng/ml, which was significantly below the reference mean of 26.4 (SD 13.2) ng/ml (p<0.001). Vitamin D deficiency (25(OH)D concentration 相似文献   

Vitamin D status, seasonal variations, parathyroid adenoma weight and bone mineral density in primary hyperparathyroidism

BACKGROUND: Primary hyperparathyroidism (PHPT) and vitamin D insufficiency are common conditions that can occur in combination. However, low plasma 25-hydroxyvitamin D (25OHD) may also enhance the risk of PHPT or modify disease severity. AIM: To compare the risk of vitamin D insufficiency and deficiency stratified by age, sex and season between PHPT patients and controls and to assess associations between plasma 25OHD and adenoma weight, biochemical variables, bone mineral density (BMD) and clinical complications. DESIGN: Cross-sectional study. MATERIAL: A total of 289 consecutive Caucasian patients with PHPT aged 65.9 (24-92) years, 289 sex-, age- and season-matched normocalcaemic controls and 187 healthy adult blood donors. PHPT diagnosis was confirmed in 214 by neck exploration. RESULTS: Vitamin D insufficiency (plasma 25OHD < 50 nmol/l) was observed in 81% of PHPT patients compared with 60% of sex- and age-matched controls (P < 0.001) and 35% of blood donors (P < 0.001). During summer, 77%vs. 53% (P < 0.001) and 4% (P < 0.001), respectively, had vitamin D insufficiency. Average plasma 25OHD was 41 (range 9-87) nmol/l among 27 PHPT patients compared with 87 (21-173) nmol/l (P < 0.001) among aged-matched blood donors. During winter, 86%vs. 66% (P < 0.001) and 71% (P < 0.05), respectively, had vitamin D insufficiency. Vitamin D deficiency (plasma 25OHD < 25 nmol/l) was observed in 33% of PHPT patients compared with 20% of age- and sex-matched controls (P < 0.001) and 13% of blood donors (P < 0.001). Both PHPT patients and controls showed seasonal variations in 25OHD related to the average number of sun hours, but values were lower in PHPT patients at all calendar months. In PHPT patients low plasma 25OHD was associated with higher plasma levels of calcium, PTH and alkaline phosphatase and with lower renal calcium excretion, femoral neck and forearm BMD. No association was found between plasma 25OHD and adenoma weight (total or divided into tertiles). There was a trend towards increased risk of osteoporotic fractures (P < 0.08) with low plasma 25OHD. CONCLUSION: Vitamin D insufficiency and deficiency are common findings in PHPT and occur more often than in a sex- and age-matched control group referred from general practice and in normal blood donors irrespective of season. Low plasma 25OHD levels are associated with an aggravated clinical presentation of PHPT but do not affect adenoma size.     

Vitamin D status, parathyroid hormone and bone mineral density in patients with inflammatory bowel disease

BACKGROUND: Although the pathogenesis of osteoporosis in inflammatory bowel disease (IBD) is not established, vitamin D deficiency and disturbances in calcium metabolism are thought to be of importance, especially in Crohn disease (CD). Vitamin D status is assessed and the relation between indices of calcium metabolism, including 25-hydroxyvitamin D and parathyroid hormone concentrations. and bone mineral density (BMD) in CD and ulcerative colitis (UC) are examined. Sixty patients with CD and 60 with UC were investigated. Each group comprised 24 men and 36 women. METHODS: Vitamin D metabolites, parathyroid hormone and biochemical markers of bone metabolism were measured in blood and urine. Lumbar spine, femoral neck and total body BMD were measured by dual X-ray absorptiometry (DXA) and Z-scores were obtained by comparison with age- and sex-matched normal values. RESULTS: Vitamin D deficiency (25-hydroxyvitamin D3 <30 nmol/l) was present in 27% of patients with CD and in 15% with UC. Furthermore, CD patients had a significantly lower mean concentration of 25-hydroxyvitamin D3 compared with UC patients. Vitamin D status was not related to BMD at any of the skeletal sites measured. Secondary hyperparathyroidism was found in 10 out of 27 patients with CD after small-bowel resections. No differences were found in serum osteocalcin and urine pyridinoline between patients with CD and those with UC. CONCLUSIONS: Hypovitaminosis D is common in CD patients. Patients with CD and small-bowel resections are at risk of developing secondary hyperparathyroidism and low BMD.     

Effect of immobilization on vitamin D status and bone mass in chronically hospitalized disabled stroke patients.

OBJECTIVE: To assess the influence of immobilization upon vitamin D status and bone mass in chronically hospitalized, disabled, elderly patients following stroke. DESIGN: cross-sectional study. SETTING: Department of geriatric neurology in a Japanese hospital. SUBJECTS: 129 chronically hospitalized, disabled, elderly stroke patients and 28 age-matched controls. RESULTS: We observed a deficiency of both 1,25-dihydroxyvitamin D (1,25-[OH]2D; 24.3 pg/ml) and 25-hydroxyvitamin D concentrations (25-OHD; 11.7 ng/ml) in stroke patients compared with controls. A high serum ionized calcium (mean; 2.648 mEq/l) was an independent determinant of the Barthel index (66) and 1,25-[OH]2D. When the patients were categorized into three groups by 25-OHD level (deficient, insufficient and sufficient), there was no difference in the mean 1,25-[OH]2D levels. Parathyroid hormone levels were normal or low and did not correlate with 25-OHD. Serum bone turnover variables and bone mineral density (BMD) of the second metacarpal in patients were significantly decreased compared to control subjects. Independent determinants of BMD included Barthel index, 25-OHD and 1,25-[OH]2D. CONCLUSIONS: 1,25-[OH]2D deficiency in immobilized stroke patients is not caused by substrate (25-OHD) deficiency but by hypercalcaemia. Immobilization-induced hypercalcaemia may inhibit parathyroid hormone secretion and thus 1,25-[OH]2D production, resulting in decreased BMD. Immobilization itself also may be responsible for decreased BMD. Exogenous 1,25-[OH]2D (calcitriol) rather than dietary vitamin D supplementation may be required in disabled elderly stroke patients who have a deficiency of 1,25-[OH]2D in order to prevent hip fractures, which frequently occur in this population.     

Relationships between vitamin D, parathyroid hormone and bone mineral density in inflammatory bowel disease

Objectives. To explore the relationships between vitamin D intake, serum parathyroid hormone (PTH) and 25-hydroxyvitamin D (250HD) concentrations, and bone mineral density (BMD) in inflammatory bowel disease (IBD).
Setting. A university hospital clinic in Finland.
Subjects. One hundred and fifty randomly selected patients with IBD from the hospital register and 73 healthy controls.
Measurements. BMD of the lumbar spine and the proximal femur was measured with dual energy X-ray absorptiometry. Vitamin D intake and serum levels of 250HD and PTH were determined.
Results. The IBD patients had a lower serum 250HD concentration (28.4 [SD 12.0] nmol L^-1) than the controls (36.1 [16.7] nmol L^-1; P =0.001), whereas no differences in the vitamin D intake or the serum PTH levels were found. The serum 250HD concentrations and the vitamin D intake of the patients with ulcerative colitis ( n =67) were similar to those of the Crohn's disease patients ( n =76). The patients with Crohn's disease of the small bowel had slightly, but not significantly, lower serum 250HD concentrations (25.6 [11.0] nmol L^-1) than the other Crohn's disease patients (31.4 [14.3] nmol L^-1; P =0.061). In the IBD patients, the vitamin D intake and the serum 250HD and PTH concentrations were not associated with BMD.
Conclusions. Patients with IBD have lower serum levels of 250HD than healthy controls, but similar serum PTH concentrations and vitamin D intake. Vitamin D intake, and the serum levels of 250HD and PTH are not associated with BMD, and malabsorption is unlikely to be a major factor in the aetiology of bone loss in unselected IBD patients.     

Vitamin D deficiency and secondary hyperparathyroidism: clinical and biochemical associations in older non-institutionalised Southern Tasmanians

Aim : To determine the prevalence and associations of vitamin D (25-OHD) deficiency in a sample of older Tasmanian subjects.
Methods : A cross-sectional survey of: 109 patients with a mean age of 79 years (range 60–101 years) consecutively admitted to a short stay geriatric rehabilitation ward; 52 community dwelling subjects with a mean age of 75 years (range 64–88 years). Subjects answered a questionnaire, had anthropometric measurements and underwent venepuncture.
Results : The main outcome measure was 25 hydroxy vitamin D (25-OHD) level with deficiency defined as < 28 nmol/L. Vitamin D deficiency was found in 67% and secondary hyperparathyroidism in 49% of the hospitalised group. Vitamin D deficiency was also found in 17% of the community group, in particular one in three residents of Independent Living Units was deficient. Subjects who were deficient were older (80 years vs 76 years [ p <0.001]), had lower body mass index (23.7 kg/m² vs 25.9 kg/m² [ p <0.001]) and had a lower serum albumin (35 gm/L vs 39 gm/L [ p <0.001]). Deficient subjects had poorer physical functional status ( p =0.02) and lower activity levels ( p <0.001) and reported less habitual sun exposure ( p <0.001). Biochemical measures such as parathyroid hormone, alkaline phosphatase and calcium were weakly predictive of vitamin D levels. By stepwise multiple regression analysis, the only significant predictors of vitamin D levels were the Frenchay Activity Index, albumin and calcium.
Conclusion : Vitamin D deficiency and secondary hyperparathyroidism is common in community living older people who are hospitalised in Southern Tasmania and is associated with increasing age, poor physical function and activity and low reported sun exposure.     

Low Parathyroid Hormone Levels in Bedridden Geriatric Patients with Vitamin D Deficiency

OBJECTIVES: To identify the clinical conditions associated with low parathyroid hormone (PTH) in patients with vitamin D deficiency and to evaluate the stability of the blunted PTH response to vitamin D deficiency over 6 months.
DESIGN: Secondary analysis of a randomized double-blind controlled vitamin D supplementation trial.
SETTING: Four long-term care hospitals in Helsinki, Finland.
PARTICIPANTS: Two hundred eighteen chronically bedridden patients.
MEASUREMENTS: Plasma 25-hydroxyvitamin D (25-OHD), intact PTH, amino-terminal propeptide of type I procollagen (PINP), carboxy-terminal telopeptide of type I collagen (ICTP), activities of daily living (ADLs), and body mass index (BMI) were measured at baseline and at 6 months. Patient records were reviewed for demographic data.
RESULTS: PTH was within reference values (8–73 ng/L) despite low 25-OHD level (<50 nmol/L) in 74.8% (n=163) of patients (mean age 84.5±7.5). Patients in the lowest PTH quartile (<38 ng/L) were characterized by a history of hip fractures (OR=2.9, P =0.01), low BMI (OR=0.9, P =.02), and high ICTP (OR=1.1, P =.03). PTH remained within reference values even after 6 months in 76.2% of the patients with persistent vitamin D deficiency in the placebo group.
CONCLUSION: The absence of secondary hyperparathyroidism seems to be common and persistent in frail chronically bedridden patients with vitamin D deficiency. Attenuated parathyroid function appears to be associated with immobilization that causes accelerated bone resorption. Further studies addressing the possible adverse effects of low PTH are warranted.     

Relationships among vitamin D levels, parathyroid hormone, and calcium absorption in young adolescents

BACKGROUND: Evidence suggests that vitamin D status in adults, as assessed by serum 25-hydroxyvitamin D (25-OHD), is positively associated with calcium absorption fraction and inversely associated with serum PTH. Few comparable pediatric data exist. OBJECTIVES: The objective of this study was to evaluate the relationships among vitamin D status, PTH, and calcium absorption in midpubertal boys and girls. METHODS: Calcium absorption was measured as part of an evaluation of the effects of prebiotics (inulin-type fructans) using a stable isotope method in 93 young adolescents, 12.7 +/- 1.0 yr of age, receiving diets averaging approximately 900 mg/d calcium. RESULTS: A significant positive relation to calcium absorption was found for serum 1,25-dihydroxyvitamin D (P = 0.048) and PTH (P = 0.007), but not for 25-OHD (P = 0.77). PTH was significantly inversely related to 25-OHD and was positively related to serum 1,25-dihydroxyvitamin D and osteocalcin. PTH was marginally significantly inversely related to lumbar spinal, but not whole body, bone mineral density. CONCLUSIONS: These data suggest that in adolescents, especially in the presence of vitamin D insufficiency, PTH secretion increases to adapt to higher rates of bone formation associated with growth. This results in higher serum 1,25(OH)2D concentrations and increased calcium absorption results. Vitamin D status, as reflected by the serum 25-OHD level, is not closely related to calcium absorption. Whether adaptation to low serum 25-OHD is adequate under physiologically stressful situations, including those leading to very low serum 25-OHD levels, is unknown.     

Vitamin D deficiency and osteoporosis

Osteoporosis is a disease of disequilibrium between bone formation and bone loss, and vitamin D is one of the key hormones in the regulation of bone metabolism, the major role of which is to provide the proper micro‐environment for bone mineralization. Vitamin D deficiency which has been defined by most experts as circulating 25‐hydroxyvitamin D levels of less than 20 ng/mL (50 nmol/L) is widespread all over the world. As shown by the results of recent studies, vitamin D deficiency could increase the risk of low bone mineral density or osteoporosis, muscle disorders, falls, and as a matter of course, fractures due to both osteoporosis and falls. Long‐term supplementation of vitamin D and calcium are good prevention measures for osteoporosis, falls and fractures. At the same time, they are essential components of osteoporosis management. Many studies show that sufficient vitamin D intake could increase bone mass, and decrease the risk of falls and fractures.     

Vitamin D deficiency does not alter biochemical markers of bone metabolism before or after autograft in patients with multiple myeloma

So far, only one study has demonstrated a high incidence of vitamin D deficiency in patients with multiple myeloma. Vitamin D deficiency may alter bone remodelling in myeloma. In this study, we aimed to determine the prevalence of vitamin D deficiency and to assess its impact on bone remodelling and bone mineral density before and after autologous stem cell transplantation (ASCT). Patients and methods: In 39 consecutive patients receiving high‐dose chemotherapy (melphalan 200 mg/m²) followed by ASCT for multiple myeloma, we measured before (T0) and 12 months after ASCT (T12) serum calcium, 25‐OH‐D, PTH 1‐84, bone alkaline phosphatase (bALP), serum C‐terminal cross‐linking telopeptide and lumbar spine bone mineral density (BMD). Results: Mean vitamin D levels were low: 15 ± 5 ng/mL (9–18) at T0 and 16 ± 5 ng/mL (14–22) at T12. Twenty‐six patients (68%) had vitamin D deficiency (25‐OH‐D < 20 ng/mL) at T0 and 58% at T12. Patients in the vitamin D‐deficient group had higher serum PTH levels than those in the vitamin D‐sufficient group : 71 ± 24 pg/mL vs. 52 ± 18 pg/mL (P = 0.04). Biochemical bone markers were identical in both groups at T0 and T12. Z‐score values did not significantly differ between the two groups at T0 and T12. There were no correlations between 25‐OH‐D and BMD or bone marker levels. Conclusion: Vitamin D deficiency does not impair biochemical markers of bone metabolism in patients with multiple myeloma, before or after ASCT.     

Vitamin D deficiency among HIV type 1-infected individuals in the Netherlands: effects of antiretroviral therapy

Vitamin D regulates bone metabolism but has also immunoregulatory properties. In HIV-infected patients bone disorders are increasingly observed. Furthermore, low 1,25(OH)(2)D(3) levels have been associated with low CD4(+) counts, immunological hyperactivity, and AIDS progression rates. Few studies have examined the vitamin D status in HIV-infected patients. This study will specifically focus on the effects of antiretroviral agents on vitamin D status. Furthermore, the effect of vitamin D status on CD4 cell recovery after initiation of HAART will be evaluated. Among 252 included patients the prevalence of vitamin D deficiency (<35 nmol/liter from April to September and <25 nmol/liter from October to March) was 29%. Female sex, younger age, dark skin, and NNRTI treatment were significant risk factors in univariate analysis, although in multivariate analyses skin pigmentation remained the only independent risk factor. Median 25(OH)D(3) levels were significantly lower in white NNRTI-treated patients [54.5(27.9-73.8) nmol/liter] compared to white PI-treated patients [77.3 (46.6-100.0) nmol/liter, p = 0.007], while among nonwhites no difference was observed. Both PI- and NNRTI-treated patients had significantly higher blood PTH levels than patients without treatment. Moreover, NNRTI treatment puts patients at risk of elevated PTH levels (>6.5 pmol/liter). Linear regression analysis showed that vitamin D status did not affect CD4 cell recovery after initiation of HAART. In conclusion, 29% of the HIV-1-infected patients had vitamin D deficiency, with skin color as an independent risk factor. NNRTI treatment may add more risk for vitamin D deficiency. Both PI- and NNRTI-treated patients showed higher PTH levels and might therefore be at risk of bone problems. Evaluation of 25(OH)D(3) and PTH levels, especially in NNRTI-treated and dark skinned HIV-1-infected patients, is necessary to detect and treat vitamin D deficiency early.     

High prevalence of vitamin D deficiency in Japanese female patients with Graves' disease

We reported previously that vitamin D deficiency is a causal mechanism of postoperative tetany in patients with Graves' disease. The aim of the present study was to determine the prevalence of vitamin D deficiency by reviewing serum 25(OH)D levels in 208 patients with Graves' disease (146 women, 62 men) during a 1 year period. Serum 25(OH)D levels were significantly lower (p < 0.001) in female Graves' patients (31.8 +/- 13.3 nmol/l) than in male patients (41.3 +/- 15.0 nmol/l). Vitamin D deficiency (defined as a serum 25(OH)D value below 25 nmol/l) was found in 40% of female patients and in 18% of male patients (p < 0.005). There was a significant seasonal variation in the 25(OH)D concentrations in female patients [amplitude 6.38 (95% CI, 5.42-7.56)], with values below 25 nmol/l found in 58% of female patients during the winter months. There were significant (p < 0.001) differences in serum 25(OH)D levels between age groups in the female patients. The concentrations were lowest in patients in their twenties (25.1 +/- 8.2 nmol/l) and highest in patients in their fifties and sixties (43.2 +/- 13.7 nmol/l). Serum 25(OH)D concentrations might be monitored in patients with Graves' disease during antithyroid drug therapy, and vitamin D and/or calcium supplements are recommended for patients with vitamin D deficiency.     

Is the recommended daily allowance for vitamin D too low for the homebound elderly?

A population of sunlight-deprived elderly was studied to determine the daily intake of vitamin D and whether dietary intake was sufficient to maintain a normal vitamin D status. Twenty-two subjects over 65 years old with serum creatinine less than 180 mumols/L and confined indoors for more than 6 months were chosen from the community and a nursing home in Southeast Baltimore. Three-day food records were obtained along with serum levels of 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D (1,25-(OH)2 D), and intact parathyroid hormone (PTH). The mean daily vitamin D intake was over twofold greater than the adult Recommended Daily Allowance (RDA) of 200 IU. The mean 25-OHD level was 40 nmol/L (normal 25-138 nmol/L) with seven patients less than 25 nmol/L. Of these participants with 25-OHD values less than 25 nmol/L, the mean vitamin D intake was 467 IU (range 36-1096 IU). We conclude that the current RDA seems inadequate for many older individuals who do not get sun exposure. This particular population of elderly is at risk to develop vitamin D deficiency and the associated complications.     

Risk factors for vitamin D deficiency in HIV-infected patients in the south central United States

We evaluated the prevalence of serum 25-hydroxyvitamin D [25(OH)D] deficiency and the risk factors for vitamin D deficiency in HIV-infected patients in the South-Central United States. The study consisted of a cross-sectional assessment of vitamin D levels in HIV-infected patients receiving routine clinical care from a private practice in Houston, Texas (latitude 29°N). Vitamin D deficiency was defined as 25(OH)D less than 20?ng/ml (<50?nmol/liter). Two-hundred enrolled patients were surveyed with a vitamin D questionnaire to determine daily supplemental vitamin D intake, dietary vitamin D intake, and average sunlight exposure (minutes/day). Multivariate logistic regression analysis was used to determine significant risk factors for vitamin D deficiency. Median 25(OH)D was 15.5?ng/ml (interquartile range 10.9-24.6) for the total population (n=200). Approximately, two-thirds (64%) of patients had vitamin D deficiency and 20.5% had severe vitamin D deficiency [25(OH)D <10?ng/ml or <25?nmol/liter]. In univariate analysis, African-American race, current tobacco use, increased body mass index (BMI), lower serum calcium level, no supplemental vitamin D use, and low daily supplemental and total daily vitamin D intake were significantly associated with vitamin D deficiency. In multivariate analysis, African-American race [adjusted odds ratio (AOR) 3.53 (95% confidence interval (CI) 1.83-6.82)], higher BMI [AOR 1.07 (95% CI 1.002-1.139)], and low daily vitamin D supplemental intake [AOR 0.997 (95% CI 0.996-0.999)] were significantly associated with vitamin D deficiency. No HIV factors including antiretroviral class use were significantly associated with either vitamin D deficiency or severe vitamin D deficiency. Vitamin D deficiency and severe vitamin D deficiency were highly prevalent in this HIV population. In the HIV population, African-Americans or patients with a high BMI may benefit from vitamin D supplementation.     

Vitamin D deficiency in general medical inpatients in summer and winter

Background: Vitamin D deficiency is common in various populations worldwide. Adverse effects of vitamin D deficiency are the development of bone disorders; however, other diseases such as multiple sclerosis, type 1 diabetes, rheumatoid arthritis and certain cancers have also been linked to vitamin D deficiency. The general medical inpatient population is a group at increased risk of vitamin D deficiency. These patients often have coexistent risk factors for its consequences. This study aims to document a point prevalence of vitamin D deficiency in this population. Methods: Two cross‐sectional audits of patients admitted to general medicine units were carried out – the first in mid‐November at the end of winter and the second in mid‐April and May at the end of summer. Information regarding patients’ comorbidities, medication usage, previous falls and fractures was obtained and serum 25‐hydroxyvitamin D, parathyroid hormone and calcium levels were measured. Results: A total of 129 patients was studied (65 in winter and 64 in summer). Ninety‐four patients (74%) had 25‐hydroxyvitamin D levels ≤50 nmol/L. Seven patients had severe deficiency (levels ≤12.5 nmol/L). Average vitamin D levels were lower at the end of winter (35 vs 43 nmol/L, P = 0.007). Of the 37 patients receiving vitamin D supplements, 20 (54%) had 25‐hydroxyvitamin D levels ≤50 nmol/L. Conclusion: Low vitamin D levels were common in this general medical inpatient population. The average vitamin D level was lower in the patient group tested in November following winter. Supplementation of vitamin D did not uniformly prevent deficiency.