Vitamin D inadequacy in French osteoporotic and osteopenic women

ObjectiveStudies have shown that low serum vitamin D levels are associated with secondary hyperparathyroidism, which decreases bone strength and increases fracture risk, most notably after 50 years of age. The objective of this study was to evaluate the vitamin D status of postmenopausal women in France.MethodsWe conducted a cross-sectional observational study of 1292 menopausal women with osteoporosis or osteopenia. The age range was 52–94 years. Serum 25-OH-vitamin D was assayed in each patient. Based on data in the literature, we used four 25-OH-D cutoffs to define vitamin D deficiency: 30, 50, 75, and 80 nmol/L (<12, <20, <30, and <32 ng/ml).ResultsMean serum 25-OH-D was 51.5 ± 26.1 nmol/L (about 20.6 ± 10.4 ng/ml). In the 343 (26.5%) patients taking supplemental vitamin D with or without supplemental calcium, the mean serum 25-OH-D level was significantly higher than in the other patients (65.0 ± 26.0 ng/ml vs. 46.6 ± 18.6 ng/ml; P < 0.001). In the subgroup not taking vitamin D supplements, the prevalence of vitamin D deficiency was 27.3%, 54.1%, 89.9%, and 93.2% with the 30, 50, 75, and 80 nmol/L cutoffs, respectively. The mean 25-OH-D level varied across seasons (P < 0.001), with the highest value being obtained in summer (53.4 ± 18.7 nmol/L; about 21.3 ± 7.5 ng/ml).ConclusionVitamin D deficiency is common among postmenopausal women with osteoporosis or osteopenia in France.     

Hypovitaminosis D and Bone Mineral Metabolism and Bone Density in Hyperthyroidism

Little is known about the impact of concomitant vitamin D deficiency on bone mineral density in hyperthyroidism. Therefore, we evaluated bone mineral measures in vitamin D–deficient and sufficient patients with hyperthyroidism. Thirty newly diagnosed consecutive patients with hyperthyroidism were included. Blood samples were used for measurement of calcium, phosphate, alkaline phosphatase, 25-hydroxy vitamin D [25(OH) D], and parathyroid hormone (PTH). Bone mineral density (BMD) was measured at the hip, spine, and forearm. The patients were divided into vitamin D–deficient (<25 nmol/L) and vitamin D–sufficient groups (≥25 nmol/L). Eight (26.6%) patients had 25(OH) D levels less than 25 nmol/L, with mean ± standard deviation (SD) level of 16.5 ± 3.2 (vitamin D–deficient group 1), and the remainder had a mean ± SD of 46.0 ± 13.5 nmol/L (vitamin D–sufficient group 2). Serum-intact PTH levels were significantly higher in group 1 compared with those in group 2 (31.2 ± 16.3 vs 18.0 ± 13.1 pg/mL; p = 0.041). In the vitamin D–deficient group, the mean BMD T-scores were in the osteoporotic range at hip and forearm (?2.65 ± 1.13 and ?3.04 ± 1.3) and in the osteopenia range at lumbar spine (?1.83 ± 1.71). However, in vitamin D–sufficient group, the mean BMD T-scores were in the osteopenia range (?1.64 ± 1.0, ?1.27 ± 1.6, and ?1.60 ± 0.7) at hip, forearm, and lumbar spine, respectively. The mean BMD Z-scores were also significantly lower in vitamin D–deficient group compared with those in vitamin D–sufficient group. Finally, BMD values (gm/cm²) at the hip and forearm were significantly lower in the vitamin D–deficient group compared with those in the vitamin D–sufficient group. In conclusion, hyperthyroid patients with concomitant vitamin D deficiency had lower BMD compared with vitamin D–sufficient patients.     

25 hydroxyvitamin D serum levels influence adequate response to bisphosphonate treatment in postmenopausal osteoporosis

It remains unclear whether vitamin D sufficiency optimizes response to bisphosphonate (BP) treatment in postmenopausal osteoporosis. We evaluated the role and possible mechanisms of vitamin D in adequate response to standard BP treatment for postmenopausal osteoporosis.MethodsWe included 120 postmenopausal osteoporotic women (aged 68 ± 8 years) receiving BP (alendronate or risedronate) at their annual follow-up, performing complete anamnesis, including treatment adherence, use of vitamin D supplements, and previous falls and fractures during the last year. We analyzed the evolution of bone mineral density (BMD) during this period and serum PTH and 25 hydroxyvitamin D (25(OH)D) and urinary NTx levels. Patients were classified as inadequate responders to antiosteoporotic treatment based on BMD loss > 2% and/or the presence of fragility fractures during the last year.ResultsThirty percent of patients showed inadequate response to BP treatment, with significantly lower levels of 25(OH)D (22.4 ± 1.3 vs. 26.6 ± 0.3 ng/ml, p = 0.01), a higher frequency of 25(OH)D levels < 30 ng/ml (91% vs. 69%, p = 0.019) and higher urinary NTx values (42.2 ± 3.9 vs. 30.9 ± 2.3 nM/mM, p = 0.01). Patients with 25(OH)D > 30 ng/ml had a greater significant increase in lumbar BMD than women with values < 30 ng/ml (3.6% vs. 0.8%, p < 0.05). The probability of inadequate response was 4-fold higher in patients with 25(OH)D < 30 (OR, 4.42; 95% CI, 1.22–15.97, p = 0.02).ConclusionsInadequate response to BP treatment is frequent in postmenopausal women with osteoporosis as is vitamin D insufficiency, despite vitamin D supplementation. Maintenance of 25(OH)D levels > 30 ng/ml is especially indicated for adequate response to BP treatment.     

Wintertime Vitamin D Deficiency in Male Adolescents: Effect on Parathyroid Function and Response to Vitamin D3 Supplements

The first part of this study consisted of an 18 month follow-up of the vitamin D status and parathyroid function in a group of 54 French male adolescents, aged from 13 to 16 years old and all pupils of a jockey training school. During the 18 month period four samplings were made, one every 6 months. The first was during September of the first year, the second and third during March and October of the second year, and the last in March of the third year. Therefore we had two main periods: summer and winter. The summer 25-hydroxyvitamin D (25(OH)D) concentrations were higher (71.6 ± 19.9 and 52.4 ± 16.5 nmol/l) than the winter ones (20.4 ± 6.9 and 21.4 ± 6.1 nmol/l). Conversely, the winter intact parathyroid hormone (iPTH) serum levels (4.18 ± 1.18 and 4.11 ± 1.35 pmol/l) were higher than the summer ones (2.44 ± 0.82 and 2.71 ± 0.71 pmol/l). At the two winter time points the 25(OH)D concentrations were lower than 25 nmol/l (10 ng/ml) in 72% (2nd year) and 68% (3rd year) of the adolescents. In the second part of the study we tried a vitamin D₃ supplementation procedure designed to maintain the 25(OH)D and iPTH postsummer serum levels throughout the winter. Pairs of male adolescents matched for height, weight and Tanner pubertal stage were randomly assigned to either vitamin D₃ supplementation (2.5 mg, i.e., 100 000 IU) administered orally at three specific periods (end of September, November and January) or no vitamin D₃ treatment (control subjects). Blood was collected just before the first intake of vitamin D₃ and 2 months after the last intake (March). The control subjects had blood drawn at the same time points. In the vitamin D₃-treated subjects, the concentrations of 25 (OH)D (55.3 ± 11.5 nmol/l) and of iPTH (3.09 ± 1.16 pmol/l) in March and September (53.8 ± 12.3 nmol/l and 2.75 ± 1.26 pmol/l) were not significantly different. In the control subjects, March 25(OH)D levels (21.0 ± nmol/l were low, with values below 25 nmol/l in 78% of subjects, and iPTH concentrations (3.97 ± 1.08 pmol/l) were significantly (p<0.001) higher than in September (2.91 ± 0.81 pmol/l). The constant vitamin D wintertime deficiency and wintertime rise in iPTH in adolescent French males throughout puberty has been demonstrated. In adolescents with low dairy calcium intakes, the vitamin D₃ treatment was sufficient to maintain 25(OH)D concentrations at their summer levels throughout winter and to prevent an excessive wintertime rise in iPTH levels. Received: 6 February 2001 / Accepted: 9 May 2001     

Vitamin D insufficiency: evaluation of an oral standardized supplementation using 100,000 IU vials of cholecalciferol, depending on initial serum level of 25OH vitamin D

ObjectivesThere is no protocol of vitamin D supplementation used worldwide due to a great disparity of vitamin D supplements available in different countries. The aim of this study was to evaluate the efficiency of the protocol most often used in France to correct vitamin D deficiency defined by a serum 25-hydroxy vitamin D (25OHD) level of less than 30 ng/mL.MethodsThis was a pragmatic multicentric study of vitamin D supplementation in 257 osteopenic/osteoporotic, vitamin D deficient patients who received 100,000 UI vitamin D3 vials every two weeks according to their initial serum 25OHD level (four vials when 25OHD less than 10 ng/mL, three when 25OHD was 10–19 ng/mL, two when 25OHD was 20–29 ng/mL). Blood samples were obtained at baseline, one (M1), two (M2), and three months (M3), after the end of the supplementation protocol.ResultsAt M1, 198/257 (77%) patients had a serum 25OHD level more than 30 ng/mL. Eighty-five percent of those with a BMI less than 25 kg/m² had a 25OHD concentration more than 30 ng/mL, whereas only 66% of those with a BMI more than 25 had a level more than 30 ng/mL. At M2 and M3, 25OHD levels decreased significantly with 55% and 46% having still a level more than 30 ng/mL respectively, without any significant difference according to the initial 25OHD level.ConclusionThis protocol was effective in rising serum 25OHD of most vitamin D insufficient patients with a BMI less than 25 kg/m², but not in overweight patients. As almost one half of our patients had a serum 25OHD level less than 30 ng/mL at M2, we suggest that regular doses should be started quite soon after this initial supplementation.     

Estimates of optimal vitamin D status

Vitamin D has captured attention as an important determinant of bone health, but there is no common definition of optimal vitamin D status. Herein, we address the question: What is the optimal circulating level of 25-hydroxyvitamin D [25(OH)D] for the skeleton? The opinions of the authors on the minimum level of serum 25(OH)D that is optimal for fracture prevention varied between 50 and 80 nmol/l. However, for five of the six authors, the minimum desirable 25(OH)D concentration clusters between 70 and 80 nmol/l. The authors recognize that the average older man and woman will need intakes of at least 20 to 25 mcg (800 to 1,000 IU) per day of vitamin D₃ to reach a serum 25(OH)D level of 75 nmol/l. Based on the available evidence, we believe that if older men and women maintain serum levels of 25(OH)D that are higher than the consensus median threshold of 75 nmol/l, they will be at lower risk of fracture.     

Correction of preoperative vitamin D deficiency after Roux-en-Y gastric bypass surgery

BackgroundTo evaluate the adequacy of supplementation to correct preoperative vitamin D deficiency in adult patients during the year after Roux-en-Y gastric bypass (RYGB) surgery.MethodsThe medical records were reviewed and the preoperative and 12-month postoperative serum 25-hydroxyvitamin D [25(OH)D] levels were compared in patients who underwent RYGB from 2002 to 2004. The serum 25(OH)D levels were defined as being optimal (≥80 nmol/L), suboptimal (50–79 nmol/L), or deficient (<50 nmol/L). Patients with deficient 25(OH)D levels were prescribed 50,000 IU ergocalciferol weekly. The remaining patients averaged 710 IU supplemental vitamin D intake daily.ResultsThe mean patient age was 43.8 ± 10.7 years, and the mean preoperative body mass index was 51.8 ± 9.8 kg/m². Of the 95 patients with baseline and 12-month 25(OH)D levels, 89% were women. The mean preoperative 25(OH)D level was 49.7 ± 26.5 nmol/L; 34% had suboptimal 25(OH)D levels and 54% had deficient levels before surgery. Twelve months after surgery, those receiving 50,000 IU weekly (n = 40) had a mean 25(OH)D level of 69.2 ± 22.2 nmol/L; 63% had suboptimal and 8% deficient levels. Those taking 710 IU daily (n = 55) had a mean 25(OH)D level of 85.5 ± 33.0 nmol/L; 44% had suboptimal and 6% deficient levels.ConclusionVitamin D deficiency is prevalent in RYGB patients before surgery. The vitamin D status improved markedly after RYGB surgery with either 710 IU vitamin D daily or 50,000 IU weekly. Current supplementation practices do not appear to optimize the serum 25(OH)D levels and need to be more closely examined.     

Impact of demographic,environmental, and lifestyle factors on vitamin D sufficiency in 9084 Japanese adults

BackgroundLittle is known about correlates of vitamin D status in Asian populations. In this study, we established the prevalence of vitamin D sufficiency in the Murakami region (latitude N38°13′) in Niigata, Japan, and examined demographic, environmental, and lifestyle factors that might be associated with vitamin D sufficiency, with the aim of clarifying the relative contributions of previously described determinants of vitamin D status as well as identifying new determinants in this Japanese population.MethodsThis study involved a cross-sectional analysis of baseline data obtained from a cohort study conducted in 2011–2013. Participants were 9084 individuals aged between 40 and 74 years who provided blood samples for the determination of plasma 25-hydroxyvitamin D [25(OH)D] concentrations. Lifestyle information was obtained from 8498 participants, with some missing values regarding different lifestyle factors. Multiple logistic regression analysis was used to obtain odds ratios for vitamin D sufficiency, which was defined as a plasma 25(OH)D concentration ≥ 75 nmol/L.ResultsThe prevalence of vitamin D sufficiency (i.e., plasma 25(OH)D concentration ≥ 75 nmol/L) was 9.1%, and significant associations were observed with male gender (P < 0.0001; OR = 2.37, 95% CI: 1.84–3.05), older age (P for trend < 0.0001), lower BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0138), higher vitamin D intake (P for trend = 0.0467), summer season (P for trend < 0.0001), longer duration outdoors (P for trend = 0.0026), no sunscreen use (P = 0.0135; OR = 1.40, 95% CI: 1.07–1.82), higher salmon consumption (P for trend < 0.0001), higher alcohol consumption (P for trend < 0.0001), and lower coffee consumption (P for trend = 0.0025). Unlike other populations previously reported, vitamin D sufficiency was associated with older age.ConclusionsThe prevalence of vitamin D sufficiency (i.e., 25[OH]D ≥ 75 nmol/L) was low (9.1%) in this Japanese population. A number of demographic, environmental, and lifestyle factors are associated with vitamin D sufficiency, and thus lifestyle modification may present an opportunity to achieve vitamin D sufficiency.     

Fractures and handicap in an adult population: A clinical study

ObjectiveTo evaluate the bone status of ambulatory patients with physical and mental handicaps before a program of fracture prevention.MethodsWe recruited 58 walking adults. We retrospectively collected the past episodes of fractures, essentially peripheral, and epilepsy. The serum calcium, albumin, 25-hydroxyvitamin D, parathormone, CTX-1 and P1NP levels were prospectively measured in 36 consecutive patients. Each patient received daily calcium and vitamin D. The vertebral status has been not evaluated.ResultsTwenty-one patients had presented at least one fracture. Thirty nine per cent of the fractures were minor (nasal bone, hands, feet). The age of patients with fractures was significantly higher than patients without fracture (46 versus 40 years, respectively; p = 0.04). Patients with fractures had a significantly increased S-P1NP (63.5 ng/ml ± 32.0 versus 41.9 ng/ml ± 20.0, respectively; p = 0.02).Nineteen patients suffered from epilepsy. We listed 23 fractures among 9 patients treated by phenobarbital and 8 fractures, which tended to be less severe among 5 patients epileptics without this drug. Minor fracture was often followed by severe fracture in case of phenobarbital treatment. This treatment was associated with a significantly lower serum calcium level (2.16 mmol/l ± 0.05, versus epileptic patients without phenobarbital 2.32 mmol/l ± 0.08, p < 0.0004).ConclusionsThe presence of a fracture, even minor, must encourage to improve the preventive and curative measures among patients with handicaps.     

High-dose oral vitamin D3 supplementation in the elderly

Summary  Daily dosing with vitamin D often fails to achieve optimal outcomes, and it is uncertain what the target level of 25-hydroxyvitamin D should be. This study found that large loading doses of vitamin D₃ rapidly and safely normalize 25OHD levels, and that monthly dosing is similarly effective after 3–5 months. With baseline 25OHD > 50 nmol/L, vitamin D supplementation does not reduce PTH levels. Introduction  There is concern that vitamin D supplementation doses are frequently inadequate, and that compliance with daily medication is likely to be suboptimal. Methods  This randomized double-blind trial compares responses to three high-dose vitamin D₃ regimens and estimates optimal 25-hydroxyvitamin D (25OHD) levels, from changes in parathyroid hormone (PTH), and procollagen type I amino-terminal propeptide (P1NP) in relation to baseline 25OHD. Sixty-three elderly participants were randomized to three regimens of vitamin D supplementation: a 500,000-IU loading dose; the loading dose plus 50,000 IU/month; or 50,000 IU/month. Results  The Loading and Loading + Monthly groups showed increases in 25OHD of 58 ± 28 nmol/L from baseline to 1 month. Thereafter, levels gradually declined to plateaus of 69 ± 5 nmol/L and 91 ± 4 nmol/l, respectively. In the Monthly group, 25OHD reached a plateau of ~80 ± 20 nmol/L at 3–5 months. There were no changes in serum calcium concentrations. PTH and P1NP were only suppressed by vitamin D treatment in those with baseline 25OHD levels <50 and <30 nmol/L, respectively. Conclusions  Large loading doses of vitamin D₃ rapidly and safely normalize 25OHD levels in the frail elderly. Monthly dosing is similarly effective and safe, but takes 3–5 months for plateau 25OHD levels to be reached.     

Impact of vitamin D supplementation on markers of bone mineral metabolism in term infants

25-Hydroxyvitamin D (25OHD) may influence bone turnover. We compared the dynamics of bone markers in 30 infants on vitamin D supplementation (? 550 IU/day) with different degrees of hypovitaminosis D (25OHD < 11 ng/ml — deficiency vs. ≥ 11 < 20 ng/ml — insufficiency). Baseline and follow-up (after 10 weeks), 25OHD, 1,25-dihydroxyvitamin D (1,25(OH)₂D), alkaline phosphatase (ALP), PTH, osteocalcin (OC), N-terminal propeptide of type I procollagen (PINP), C-terminal telopeptide of type I collagen (CTX), and amino-terminal propeptide of C-type natriuretic peptide (NT-proCNP) were measured. None of the newborns had craniotabes, hypocalcemia or hyperparathyroidism. The median (Q1;Q3) 25OHD increased from a baseline of 8.45 (7;11.9) ng/ml to 54.6 (34.7;67.3) ng/ml (p < 0.001). The baseline 25OHD negatively correlated with total increment of 25OHD (r = ? 0.54; p = 0.002). There were changes in ALP (241 vs. 331 IU; p < 0.001), 1,25(OH)₂D (48 vs. 95.5 pg/ml, p < 0.001), OC (88.8 vs. 159.1 ng/ml, p < 0.001), PINP (3886 vs. 2409 ng/ml; p < 0.001), CTX (1.6 vs. 1.1 ng/ml; p < 0.001), and NT-proCNP (75.1 vs. 35.1 pmol/l; p < 0.001). Vitamin D deficient infants at baseline, compared to the insufficient group, revealed significantly higher percentage changes for 25OHD (745% vs. 167%, p < 0.0001), OC (113% vs. 40%, p < 0.05) and 1,25(OH)₂D (95% vs. 58%, p < 0.05). Conclusions: Vitamin D supplements had little to no impact on markers of bone turnover in term infants in the first few months of life, with the exception of osteocalcin. Ten weeks of cholecalciferol supplementation at a dose of 550 IU/day led to a marked increase of 25OHD concentration. The magnitude of 25OHD increment was inversely related to vitamin D status at baseline. Irrespective of the severity of vitamin D deficiency, a secondary hyperparathyroidism with elevated iPTH, ALP, phosphaturia or hypophosphatemia was not observed in the studied neonates.     

Efficacy of different doses and time intervals of oral vitamin D supplementation with or without calcium in elderly nursing home residents

Summary The effect of equivalent oral doses of vitamin D3 600 IU/day, 4200 IU/week and 18,000 IU/month on vitamin D status was compared in a randomized clinical trial in nursing home residents. A daily dose was more effective than a weekly dose, and a monthly dose was the least effective. Introduction It is assumed that equivalent daily, weekly or monthly doses of vitamin D3 equally influence vitamin D status. This was investigated in a randomized clinical trial in nursing home residents. Methods The study was performed in ten nursing homes including 338 subjects (76 male and 262 female), with a mean age of 84 (± SD 6.3 years). They received oral vitamin D3 either 600 IU/day, or 4200 IU/week, or 18,000 IU/month or placebo. After 4 months, calcium was added during 2 weeks, 320 mg/day or 640 mg/day or placebo. Outcome: serum levels of 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH) and bone turnover markers. Statistical approach: linear multilevel analysis. Results At baseline, mean serum 25(OH)D was 25.0 nmol/L (SD 10.9), and in 98%, it was lower than 50 nmol/L. After 4 months, mean serum 25(OH)D levels increased to 62.5 nmol/L (after daily vitamin D3 69.9 nmol/L, weekly 67.2 nmol/L and monthly 53.1 nmol/L, P < 0.001 between groups). Median serum PTH levels decreased by 23% (p < 0.001). Bone turnover markers did not decrease. Calcium supplementation had no effect on serum PTH and bone turnover. Conclusion Daily vitamin D was more effective than weekly, and monthly administration was the least effective.     

Vitamin D levels in post-menopausal Korean women with a distal radius fracture

IntroductionThe purpose of this study was to investigate serum levels of vitamin D in post-menopausal Korean women with a distal radius fracture (DRF) and to determine if there is any association between vitamin D levels and bone-related variables such as bone mineral densities (BMDs), serum parathyroid hormone (PTH) levels and several bone turnover markers.Materials and methodsThe data of 104 postmenopausal women surgically treated for a distal radius fracture (DRF group) and 107 age-matched control patients without a fracture (control group) were compared. Serum vitamin D levels (25-hydroxycholecalciferol, 25(OH)D₃) were compared between the groups with consideration of age and seasonal variations. BMDs, serum PTH and several bone turnover markers, including serum osteocalcin, C-telopeptide and urine N-telopeptide, were measured and analysed to find any association with vitamin D levels.ResultsThe mean 25(OH)D₃ level was significantly lower in the DRF group compared to the control group (p < 0.001). In particular, patients in their sixth and seventh deciles in the DRF group had significantly lower 25(OH)D₃ levels than patients in the control group (p = 0.001 and 0.013, respectively). When seasonal variation was considered, significant differences of 25(OH)D₃ levels were found between the groups in autumn and winter. Hip BMDs were significantly lower in the DRF group than in the control group, and there was a positive correlation between serum 25(OH)D₃ levels and hip BMDs. Bone turnover markers were not significantly different between the two groups, although serum PTH levels were marginally higher in the DRF group (p = 0.08).ConclusionsPost-menopausal Korean women with a DRF were found to have significantly lower serum vitamin D levels than the control group, and vitamin D levels were particularly lower in women in their sixth and seventh deciles who may be a good target group for prevention of future fractures. Future investigation should focus on determining whether vitamin D supplementation can be helpful in preventing future fractures in patients with a DRF.     

High prevalence of vitamin D deficiency among middle-aged and elderly individuals in northwestern China: Its relationship to osteoporosis and lifestyle factors

PurposeVitamin D deficiency has reached epidemic proportions; this deficiency has been associated with osteoporosis and certain lifestyle factors in adults. This relationship is not well documented among the Lanzhou population in northwest China. This study sought to determine the prevalence of vitamin D deficiency and its risk factors in addition to its relationship with osteoporosis in a Chinese population living in Lanzhou.MethodsThis cross-sectional study involved 2942 men and 7158 women aged 40–75 years who were randomly selected from 3 communities in the Lanzhou urban district and examined medically. Levels of 25-hydroxy-vitamin D [25(OH)D] and other parameters were measured according to detailed inclusion criteria. Vitamin D deficiency was defined as serum 25(OH)D levels below 20 ng/mL. Calcaneus bone mineral density (BMD) was measured by quantitative ultrasound (QUS).ResultsThe prevalence of vitamin D deficiency (25(OH)D levels < 20 ng/mL) was present in 75.2% of the entire study population. Vitamin D deficiency was more prevalent in women (79.7%) than in men (64%; P < 0.001). Multiple logistic regression analysis revealed that the significant predictors of vitamin D deficiency included coronary heart disease (CHD), obesity, dyslipidemia, older age, female sex, and smoking (all P < 0.05), whereas tea intake, moderate physical activity, milk intake, vitamin D supplementation and sun exposure were protective (all P < 0.05). No significant difference in calcaneus BMD measured by QUS was noted between subjects with < 20 ng/mL and ≥ 20 ng/mL vitamin D levels (0.53 ± 0.13 vs. 0.54 ± 0.13; P = 0.089). The risk of having osteoporosis did not increase when vitamin D levels decreased from ≥ 20 ng/mL to < 20 ng/mL after multiple adjustments (OR = 1.00; 95% CI 0.85–1.16; P = 0.357).ConclusionsVitamin D deficiency is prevalent in the middle-aged and elderly northwestern Chinese population and is largely attributed to CHD, obesity, dyslipidemia, older age, female sex, and smoking. Reduced 25(OH)D levels are not associated with an increased osteoporosis risk.     

Hip fracture type: Important role of parathyroid hormone (PTH) response to hypovitaminosis D

ObjectiveTo investigate whether clinical and laboratory characteristics, including serum 25-hydroxyvitamin D (25(OH) D), PTH and parameters of mineral and bone metabolism, differ by hip fracture (HF) type.Patients and methodsWe studied prospectively 761 consecutively admitted older patients (mean age 82.3 + 8.8(SD) years; 74.9% women) with low trauma non-pathological HF. A detailed clinical examination was performed, haematologic, renal, liver and thyroid function tests, serum 25(OH)D, PTH, calcium, phosphate, magnesium, C-reactive protein (CRP) and cardiac troponin I (cTnI) measured. In a subset of 294 patients' markers of bone formation (serum osteocalcin, OC; bone specific alkaline phosphatase, BAP) and bone resorption (urinary deoxypyridinoline, DPD/Cr; N-terminal cross-linked telopeptide of type 1 collagen, NTx/Cr; both corrected to urinary creatinine, Cr) were also measured.ResultsIn the trochanteric compared to the cervical group, females were older than males and the prevalence of Parkinson's disease, mean haemoglobin and albumin levels were lower. Incidence and degree of myocardial injury (cTnl rise) and inflammatory reaction (CRP elevation) as well as length of hospital stay, need of institutionalisation or in-hospital mortality were similar in both groups. Hypovitaminosis D (25(OH)D < 50 mmol/L) was present in 77.8% of patients with cervical and in 82.1% with trochanteric HF, elevated PTH (> 6.8 pmol/L) in 30.2% and 41.3%, respectively. The associations between 25(OH)D, PTH, and parameters of mineral metabolism and bone turnover were site-specific. In multivariate analyses, PTH (both as a continuous or categorical variable) response to hypovitaminosis D was a strong independent predictor of HF type. Coexistence of vitamin D deficiency (25(OH) D< 25 nmol/L) and elevated PTH predicts trochanteric HF while blunted PTH response predicts cervical HF (OR = 3.5; 95% CI 1.5–80; p = 0.005). PTH response and phosphate status (above or below median level) correctly discriminated HF type in 73.8% of patients with vitamin D deficiency.ConclusionsHF type is significantly associated with PTH response to hypovitaminosis D and impaired phosphate homeostasis. We detected only minor differences between two main HF types with regard to a wide range of clinical and routine laboratory variables as well as short-term outcomes.     

Vitamin D Status During Puberty in French Healthy Male Adolescents

The vitamin D status was determined on one to four occasions either after summer (September–October) or after winter (March–April) in 175 male adolescents (13–17 years), resulting in 394 measurements of serum 25-hydroxyvitamin D (25(OH)D) and intact parathyroid hormone (iPTH). The subjects lived in a rural area to the north of Paris (49° N). After summer the 25(OH)D concentration was 58.5 ± 18.0 nmol/l (mean ± SD), while after winter it had fallen to 20.6 ±6.0 nmol/l (p= 0.0001). Meanwhile the iPTH concentration was 2.76 ± 0.97 pmol/l (mean ± SD) after summer and increased to 4.20 ± 1.21 pmol/l after winter (p= 0.0001). All the results were pooled and a nonlinear population model with random parameters was used to describe the relationship between serum iPTH and 25(OH)D. When the concentration of 25(OH)D was higher than 83 nmol/l, an iPTH mean ‘plateau’ level at 2.48 pmol/l was reached. When 25(OH)D concentrations fell below 83 nmol/l, the increase in iPTH concentration accelerates, and when the mean 25(OH)D concentration was equal to or lower than 10 nmol/l the mean iPTH level (4.97 pmol/l) was twice as high as the ‘plateau’ value. Received: 26 November 1998 / Accepted: 15 February 1999     

Unusually prolonged vitamin D intoxication after discontinuation of vitamin D: possible role of primary hyperparathyroidism

A 77-year-old woman had taken 50,000 IU of vitamin D2 daily, instead of once weekly, for over 2 years. She developed severe hypercalcemia, and after stopping vitamin D, her serum 25-hydroxyvitamin D (25(OH)D) remained higher than 250 nmol/l for almost 2(1/2) years. Inappropriately high parathyroid (PTH) concentrations were particularly evident after serum calcium was suppressed to slightly above the reference range by the administration of intravenous pamidronate and prednisone. It seems that an underlying primary hyperparathyroidism that was masked initially by the hypercalcemia of vitamin D intoxication was responsible for the unusually prolonged half-life of 25(OH)D in the blood. After vitamin D2 had been stopped, the decline in serum 25(OH)D was unusually slow. In this unusual case, primary hyperparathyroidism probably prevented an appropriate increase in the vitamin D-catabolizing enzyme, 25(OH)D-24-hydroxylase, thereby slowing metabolic clearance of 25(OH) vitamin D.     

Pharmacokinetics of oral vitamin D3 and calcifediol

AimLong-term pharmacokinetics after supplementation with vitamin D₃ or calcifediol (the 25-hydroxyvitamin D₃ metabolite) is not well studied. Additionally, it is unclear whether bolus doses of vitamin D₃ or calcifediol lead to 25(OH)D₃ plasma concentrations considered desirable for fracture prevention (30 ng/mL). We therefore investigated plasma pharmacokinetics of 25(OH)D₃ during different vitamin D₃ and calcifediol supplementation regimens.MethodsIn this seven-arm, randomized, double-blind, controlled parallel-group study, 35 healthy females aged 50–70 years (5 per group) received 20 μg calcifediol or vitaminD₃ daily, 140 μg calcifediol or vitaminD₃ weekly, for 15 weeks, or a single bolus of either 140 μg calcifediol, or vitaminD₃, or both. 25(OH)D₃ plasma concentrations were quantified using LC–MS/MS in 14 clinical visits among all participants.ResultsFor daily (weekly) dosing, the area under the concentration–time curve (AUC_0–24h), which is the measure for exposure, was 28% (67%) higher after the first dose of calcifediol than after the first dose of vitamin D₃. After 15 weeks, this difference was 123% (178%). All women in the daily and weekly calcifediol groups achieved 25(OH)D₃ concentrations > 30 ng/mL (mean, 16.8 days), but only 70% in the vitamin D₃ daily or weekly groups reached this concentration (mean, 68.4 days). A single dose of 140 μg calcifediol led to 117% higher 25(OH)D₃ AUC_0–96h values than 140 μg vitamin D₃, while the simultaneous intake of both did not further increase exposure.ConclusionsCalcifediol given daily, weekly, or as a single bolus is about 2–3 times more potent in increasing plasma 25(OH)D₃ concentrations than vitamin D₃. Plasma 25(OH)D₃ concentrations of 30 ng/mL were reached more rapidly and reliably with calcifediol.     

Effects on bone mineral density of calcium and vitamin D supplementation in elderly women with vitamin D deficiency

OBJECTIVE: Calcium and vitamin D deficiency is common in older individuals, particularly those who live in nursing homes, and increases the risk of osteoporosis and fractures. METHODS: We conducted a randomized double-blind placebo-controlled study of combined supplementation with 500 mg of elemental calcium, as carbonate, and 400 IU of vitamin D bid for 12 months in women older than 65 years of age with vitamin D deficiency, defined as serum 25(OH)D concentrations 相似文献