Finding the Optimal Dose of Vitamin D Following Roux-en-Y Gastric Bypass: A Prospective, Randomized Pilot Clinical Trial

Background  Vitamin D deficiency is common following bariatric surgery and is due to a combination of baseline deficiency and postoperative malabsorption. There are few prospective studies evaluating the appropriate dose of vitamin D to prevent and treat vitamin D deficiency following bariatric surgery. Methods  We evaluated three doses of vitamin D3 (800, 2,000, and 5,000 IU/day) in a prospective, randomized pilot trial of 45 patients undergoing Roux-en-Y gastric bypass. Serum 25 hydroxy Vitamin D (25OHD), intact PTH (iPTH), calcium, and urine calcium/creatinine ratios were measured at 6, 12, and 24 months postoperatively. Due to a high dropout rate at 24 months, we focus on the 12-month data. Results  At 12 months, the 800-, 2,000-, and 5,000-IU groups had a mean ± SD increase in 25OHD of 27.5 ± 40.0, 60.2 ± 37.4, and 66.1 ± 42.2 nmol/L, respectively (p = 0.09) with a maximum increase in each group of 87.4, 114.8, and 129.8 nmol/L. Forty-four percent, 78%, and 70% achieved 25OHD levels ≥75 nmol/L (p = 0.38). Results for the 6- and 24-month time points were similar to the 12-month results. Mean weight loss at 24 months of the study was not different among groups (p = 0.52). Serum calcium did not change significantly, and there were no cases of hypercalcemia or sustained hypercalciuria. Conclusions  Higher doses of vitamin D supplementation trend towards higher levels of 25OHD. Vitamin D replacement as high as 5,000 IU /day is safe and necessary in many patients to treat vitamin D deficiency following Roux-en-Y gastric bypass yet is still suboptimal in others.     

Is there an association between periprosthetic joint infection and low vitamin D levels?

Purpose

Vitamin D is increasingly being recognized as an important mediator of immune function and may have a preventive role in the pathogenesis of periprosthetic joint infection. To the best of our knowledge, no other study has examined possible associations between periprosthetic joint infection and vitamin D deficiency. We investigated the rate of vitamin D deficiency in patients treated for periprosthetic joint infection and whether vitamin D deficiency is independent of other risk factors for vitamin D deficiency in patients with periprosthetic joint infection.

Methods

Serum 25-hydroxyvitamin D (25OHD) levels of every patient scheduled to receive a total prosthesis either of the hip, knee, or shoulder in the orthopaedic department of the Johannes-Guttenberg-University Hospital in Mainz, Germany (109 patients), were measured after admission. Furthermore, serum 25OHD levels were measured for every patient presenting with periprosthetic joint infection (n = 50) or aseptic loosening of the prosthesis (n = 31) scheduled to undergo revision surgery. The prevalence of normal (>30 ng/ml), insufficient (20–30 ng/ml), and deficient (<20 ng/ml) 25OHD levels was determined.

Results

All tested patient subgroups showed low vitamin D levels. Statistical analysis found no significant difference in vitamin D levels comparing patients with prosthesis and patients with aseptic prosthesis loosening (p = 0.58). Significant differences in 25OHD levels were found comparing patients with periprosthetic joint infection and patients scheduled for primary arthroplasty (p < 0.001). In addition, we found a significant difference (p < 0,001) in 25OHD levels of patients with periprosthetic joint infection compared with patients with aseptic prosthesis loosening.

Conclusion

We found a high frequency of vitamin D deficiency in patients being treated by primary arthroplasty and those with aseptic joint prosthetic loosening and periprosthetic joint infection. Vitamin D deficiency was severe in patients with periprosthetic joint infection.     

Preoperative vitamin D status and its effects on short-term clinical outcomes in lumbar spine surgery

BackgroundMany studies have found that vitamin D deficiency has a high incidence rate worldwide, but we found few studies on the role of vitamin D in spinal degenerative diseases. We investigated the determinants of preoperative vitamin D deficiency and its effects on postoperative outcomes among patients undergoing elective lumbar spine surgery.Methods360 patients treated from July 2017 to July 2018 were retrospectively identified for inclusion. The patients’ fasting serum levels of 25(OH)D, N-terminal midfragment of osteocalcin (N-MID), and β typeⅠcollagen carboxyl terminal peptide (β-CTX) were measured by electrochemiluminescence before the operation. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) and Oswestry Disability Index scores (ODI) were used to evaluate the clinical outcomes. Standard demographic data and all perioperative complications occurring within 3 months follow-up after operation were recorded.ResultsThe mean serum level of 25(OH)D was 20.81 ± 8.55 ng/mL, the rates of deficiency (<20 ng/ml) was 53.6%. The abnormal proportion of N-MID and β-CTX were 8.61% and 34.44%, bone turnover markers serum level was higher in older age groups (p < 0.05). Female sex (p < 0.001), a high body mass index (BMI) (p = 0.012), lack of vitamin D supplementation (p = 0.018), smoking (p = 0.033), moderate (p < 0.001) to severe pain (p = 0.005) were significant predictors of vitamin D deficiency after the multivariate analysis. The VAS, JOA and ODI scores showed significantly better outcomes compared to deficient group at post-operative and final follow-up (p < 0.05).ConclusionVitamin D deficiency was common in patients undergoing elective lumbar spine surgery. Female sex, high BMI, lack of vitamin D supplementation, smoking and moderate to severe pain were risk factors for vitamin D deficiency. Moreover, preoperative hypovitaminosis D (<20 ng/ml) was correlated with worse surgical outcomes in short-term.     

High-Dose Vitamin D Supplementation Can Correct Hypovitaminosis D Prior to Total Knee Arthroplasty

BackgroundVitamin D deficiency in the perioperative surgical period is associated with inferior surgical outcomes. There are no established preoperative supplementation regimens in the orthopedic literature. The purpose of this study is to compare the efficacy between 2 different supplementation regimens of vitamin D prior to total knee arthroplasty.MethodsWe conducted a retrospective analysis of 174 patients identified as vitamin D deficient (25(OH)D < 30 ng/mL) who received one of 2 vitamin D supplementation protocols: (1) daily supplementation with D3 on a sliding scale from 1000 to 6000 IU or (2) a loading dose of 50,000 IU D3 weekly for 4 weeks then 2000 IU/d. Serum vitamin D levels were measured at 3 months and 1 month preoperatively.ResultsMean patient age was 65.5(±8.6) years, and 54.6% were female. Deficiency was corrected in 73.3% of patients in the loading dose group and 42.4% of patients in the daily, low-dose group [χ² (1, N = 174) = 16.53, P < .001]. Patients in the loading dose group also achieved a greater average correction in vitamin D levels.ConclusionThis is the first study to compare preoperative vitamin D supplementation protocols. A loading dose regimen of 50,000 IU weekly for 4 weeks followed by a maintenance dose of 2000 IU/d more effectively corrects vitamin D deficiency compared to a low-dose, daily regimen among total knee arthroplasty patients. We recommend this regimen for deficiency correction in patients who have been screened to be deficient in vitamin D preoperatively.     

Clinical Effect of Preoperative 25-OH-Vitamin D3 Level in Liver Transplant Recipients

BackgroundVitamin D deficiency is common in patients with chronic liver disease and is associated with increased risk of infection and mortality. This study evaluated the effects of preoperative vitamin D levels on clinical outcomes after liver transplant.MethodsThis single-center retrospective study included liver transplant recipients from June to November 2017 who had preoperative 25-OH-vitamin D3 (25-OH-D3) data. Severe vitamin D deficiency, insufficiency, and normal levels were defined as serum 25-OH-D3 concentrations of < 10 ng/mL, 10 to 20 ng/mL, and ≥ 20 ng/mL, respectively. The primary outcome was length of hospital stay; secondary outcomes included the duration of normalization of inflammatory markers after liver transplant, new infection rates, rejection rates, length of intensive care unit stay, and mortality according to preoperative 25-OH-D3 levels.ResultsAmong 219 liver transplant recipients, 67.6% were vitamin D-deficient. The mean (standard deviation) 25-OH-D3 concentration was 17.8 (13.2) ng/mL, and 65 (29.7%) patients had levels < 10 ng/mL. Patients with lower mean 25-OH-D3 levels had significantly longer intensive care unit (13.8 [21.9] days vs 5.9 [12.3] days vs 2.7 [4.6] days, P < .001) and hospital (59.0 [66.0] days vs 42.0 [67.4] days vs 27.2 [17.1] days, P = .001) stays. The incidence of new infections was higher in the vitamin D deficiency group. (46.2% vs 28.9% vs 14.1%, P < .001). A higher Nutritional Risk Screening 2002 score (adjusted odds ratio, 1.77; 95% confidence interval [CI], 1.24-2.56; P = .002) and severe vitamin D deficiency (adjusted odds ratio, 3.43; 95% CI, 1.57-7.57; P = .002) were significant risk factors for poor outcome among patients who had been in the hospital for more than 43 days.ConclusionsVitamin D deficiency before liver transplant was associated with increased intensive care unit and hospital lengths of stay. Although several factors may influence the clinical outcomes of patients with liver transplant, low vitamin D3 was an independent risk factor.     

Vitamin D levels in 577 consecutive elective foot & ankle surgery patients

BackgroundVitamin D deficiency is a global concern impacting upon large communities and certain disease populations. It can adversely affect the outcome of orthopaedic operations. We aimed to perform an audit of the Vitamin D status of patients in two centres in the United Kingdom undergoing elective foot and ankle surgery.MethodsSerum 25-hydroxyvitamin-D (vitamin D) levels were obtained prospectively in 577 consecutive elective patients undergoing elective foot and ankle surgery between October 2014 and March 2017 (29 months). Variables including age, gender, ethnicity, location, season, month and procedure type were recorded.Results577 patients were included over the study period. 62.0% were female. Mean age was 53.2 (median 54.5, range 16.7–86.6). 300 patients were treated in Northampton and 277 in Leicester. The serum 25-hydroxyvitamin-D levels for the patient group were normally distributed. The mean was 52.3 nmol/L (SD 28.0; range 7.5–175) and the median 47.5 nmol/L. 21.7% were grossly deficient, 31.9% deficient, 28.9% insufficient and 17.5% within normal range. Age, gender and procedure type did not statistically affect vitamin D levels (p = 0.5, t-test). Ethnicity, location and Winter season did affect Vitamin D levels (p < 0.05). August was the most significant month with levels significantly higher than January, February, March, April, June, November and December (p < 0.05, one-way ANOVA).ConclusionsOnly 1 in 5.7 patients had a normal Vitamin D level and 1 in 4.6 were grossly deficient. Ethnicity and patient location significantly affected Vitamin D results. Summer months were noted to demonstrate significantly the highest levels and August the highest. We did not find that age or gender affected Vitamin D levels in our cohort.     

The Effect of High-Dose Vitamin D Supplementation on Calciotropic Hormones and Bone Mineral Density in Obese Subjects with Low Levels of Circulating 25-Hydroxyvitamin D: Results from a Randomized Controlled Study

Low levels of 25-hydroxyvitamin D (25OHD) are associated with increased bone turnover and risk of fractures. Plasma 25OHD is inversely related to body mass index, and vitamin D deficiency is common in obesity. We aimed to determine whether vitamin D supplementation affects bone turnover and bone mineral density (BMD) in obese subjects. Fifty-two healthy obese men and women aged 18–50 years with plasma 25OHD levels below 50 nmol/L were randomized to 7,000 IU of cholecalciferol daily or placebo for 26 weeks. We measured plasma levels of 25OHD, parathyroid hormone (PTH), and markers of bone turnover, as well as BMD at the hip, spine, forearm, and whole body. Compared with placebo, treatment with cholecalciferol increased mean plasma 25OHD from 35 to 110 nmol/L (p < 0.00001) and significantly decreased PTH (p < 0.05). BMD increased significantly at the forearm by 1.6 ± 0.7 % (p = 0.03). The bone resorption marker C-terminal telopetide of type 1 collagen (CTX) decreased borderline significantly in the cholecalciferol group compared with the placebo group (p = 0.07). Changes in plasma 25OHD correlated inversely with changes in plasma levels of bone-specific alkaline phosphatase (r = ?0.38, p = 0.01) and CTX (r = ?0.33, p = 0.03). Changes in CTX correlated inversely with changes in spine BMD (r = ?0.45, p = 0.04). Increasing circulating 25OHD levels by cholecalciferol treatment is of importance to bone health in young obese subjects as increased levels of 25OHD are associated with a decrease in both PTH and bone turnover and with an increase in BMD at the forearm.     

Vitamin D binding protein genotype is associated with plasma 25OHD concentration in West African children

Vitamin D is well known for its role in promoting skeletal health. Vitamin D status is determined conventionally by circulating 25-dihydroxyvitamin D (25OHD) concentration. There is evidence indicating that circulating 25OHD concentration is affected by variation in Gc, the gene encoding the vitamin D binding protein (DBP). The composite genotype of two single nucleotide polymorphisms (rs7041 and rs4588) results in different DBP isotypes (Gc1f, Gc1s and Gc2). The protein configurational differences among DBP isotypes affect DBP substrate binding affinity.The aims of this study were to determine 1) Gc variant frequencies in a population from an isolated rural region of The Gambia, West Africa (n = 3129) with year-round opportunity for cutaneous vitamin D synthesis and 2) the effects of Gc variants on 25OHD concentration (n = 237) in a genetically representative sub-group of children (mean (SD) age: 11.9 (4.8) years).The distribution of Gc variants was Gc1f: 0.86, Gc1s: 0.11 and Gc2: 0.03. The mean (SD) concentration of 25OHD was 59.6 (12.9) nmol/L and was significantly higher in those homozygous for Gc1f compared to other Gc variants (60.7 (13.1) vs. 56.6 (12.1) nmol/L, P = 0.03). Plasma 25OHD and 1,25(OH)₂D concentration was significantly associated with parathyroid hormone in Gc1f-1f but not in the other Gc variants combined.This study demonstrates that different Gc variants are associated with different 25OHD concentrations in a rural Gambian population. Gc1f-1f, thought to have the highest affinity for 25OHD, had the highest 25OHD concentration compared with lower affinity Gc variants.The considerable difference in Gc1f frequency observed in Gambians compared with other non-West African populations and associated differences in plasma 25OHD concentration, may have implications for the way in which vitamin D status should be interpreted across different ancestral groups.     

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.     

Vitamin D insufficiency does not affect response of bone mineral density to alendronate

Summary  We investigated whether osteoporosis therapy with alendronate in postmenopausal patients is equally effective in patients who are vitamin D insufficient as in those who are vitamin D sufficient. We found that vitamin D insufficiency is common among patients with low bone density but that vitamin D insufficiency did not impair response to alendronate. Introduction  Treatment of vitamin D deficiency leads to significant improvements in bone mineral density (BMD); however, whether insufficiency affects BMD’s response to bisphosphonate therapy is unknown. Methods  To determine whether vitamin D insufficiency at initiation of alendronate therapy for low BMD affects treatment efficacy, we used data from 1,000 postmenopausal women randomly selected from the vertebral fracture arm (n = 2,027) of the placebo-controlled Fracture Intervention Trial of alendronate. Participants were randomly assigned to placebo (50%) or alendronate therapy and most (83%) to calcium (500 mg/day) and cholecalciferol (250 IU/day). We measured serum 25-hydroxy vitamin D (25OHD) at enrollment, then categorized baseline vitamin D status according to 25OHD concentration ( ≤ 10 ng/ml = deficient; >10 but ≤ 30 ng/ml = insufficient; >30 ng/ml = sufficient) and used linear regression to compare the effects of alendronate treatment among these categories. Results and conclusion  At baseline, participants were vitamin D sufficient (14%), insufficient (83%), and deficient (2%). We found that BMD response to therapy at total hip or spine did not vary by vitamin D status at baseline (p for heterogeneity = 0.6). We determined that vitamin D insufficiency is common among participants with low BMD. However, vitamin D status at initiation of therapy does not affect BMD’s response to alendronate, when it is coadministered with cholecalciferol and calcium. Scholar’s Grant from the National Osteoporosis Foundation (to D.M.A) and National Institutes of Health grant K23 RR020343 (to D.M.A).     

Serum 25-hydroxyvitamin D, parathyroid hormone, and bone mineral density in men: the Rancho Bernardo study

Introduction This study examined the distribution and determinants of serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) and their associations with bone mineral density (BMD) at the hip and spine in 414 older men (mean age 74 years) living in southern California.Methods At a clinic visit (1997–2000), demographic and lifestyle information, fracture history, and medication use were recorded; venous blood for serum 25OHD and PTH was obtained; and BMD was measured at the hip and spine.Results Only one man had vitamin D deficiency (25OHD <20 nmol/l), but 15.5% of the men had high parathyroid levels (PTH ≥65 pg/ml). The mean 25OHD and PTH levels were 109.0 nmol/l and 50.3 pg/ml, respectively. Overall, 21.5% used calcium and 9.7% used vitamin D supplements. Serum 25OHD decreased with age and was lowest in the winter; levels were higher in supplement users (vitamin D and/or calcium; p<0.01). Serum PTH did not vary by age or season, and it was lower in supplement users (p<0.01). After excluding 12 men who were outliers for serum 25OHD and PTH, there was no significant correlation between serum 25OHD and PTH (r=−0.05, p=0.3). In multiple adjusted models, serum 25OHD was positively associated with BMD at the hip (p=0.01) and spine (p=0.001). Serum PTH was moderately and inversely associated with BMD at the hip (p=0.04) but not at the spine (p=0.77).Conclusion We conclude that serum 25OHD is associated with bone health in older, community-dwelling men.     

Strong relationship between vitamin D status and bone mineral density in anorexia nervosa

BackgroundAnorexia nervosa (AN) is associated with impaired bone health and low bone mineral density (BMD) as a consequence of an inadequate peak bone mass in adolescence and bone loss in young adulthood. The vitamin D status with its implications for bone health in patients affected by AN has only been examined previously in small studies.ObjectiveTo evaluate the prevalence of vitamin D deficiency and test the hypothesis that patients with AN and vitamin D deficiency might have worse bone metabolism and lower bone density as compared with AN with adequate vitamin D repletion.DesignWe analysed the vitamin D status and bone metabolism in a large cohort (n = 89) of untreated patients affected by AN, with amenorrhoea.ResultsVitamin D deficiency is widespread in untreated patients with AN: 16.9% had 25OH vitamin D levels below 12 ng/ml, 36% below 20 ng/ml and 58.4% below 30 ng/ml. PTH values were higher and BMD at both femoral sites were lower in patients with vitamin D < 20 ng/ml. Progressively higher values of BMD were observed by 4 ranks of 25 OH vitamin D values (severe deficiency: < 12 ng/ml, deficiency: ≥ 12 ng/ml and < 20 ng/ml, insufficiency: ≥ 20 and < 30 ng/ml and normal: ≥ 30 ng/ml). In patients with severe vitamin D deficiency BMD at the hip were significantly lower than that measured in groups with values over 20 ng/ml (p < 0.001 for trend). The level of significance did not change for values adjusted for BMI or body weight.ConclusionWe found a strong relationship between vitamin D status and hip BMD values with additional benefits for those with 25OHD levels above 20 ng/ml. Our results support the design of a randomized placebo-controlled clinical trial on the effect of vitamin D on BMD in patients with AN. The second point, whether 25OHD should be above 20 or 30 ng/ml remains a discussion point.     

Low prevalence of vitamin D deficiency among adolescents with anorexia nervosa

Summary Fifty adolescents with AN and 200 healthy girls underwent vitamin D screening. Girls with AN reported exceptional compliance with vitamin D supplementation and PTH concentrations were lower. Vitamin D deficiency was less common in the group with AN, but when race was considered, the trend was no longer significant. Introduction The objective of this study was to determine whether patients with anorexia nervosa (AN) are more compliant with supplementation and have a lower prevalence of vitamin D deficiency than healthy controls. Methods Fifty adolescents with AN and 200 controls were compared using anthropometric and lifestyle data, serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) concentrations, and prevalence of vitamin D deficiency. Results The prevalence of deficiency (<20 ng/mL) was 2% in the AN group vs. 24% among controls (p = 0.003). 25OHD was similar among white participants with AN and white controls (39.5 vs. 36.0 ng/mL, p = 0.20), but higher than in non-white controls (20.6 ng/mL). Significantly more girls with AN reported vitamin D supplementation (86%) than the full control (14%) or white subgroup (27%) (p < 0.001). Participants with AN had lower PTH concentrations than controls, (27.8 vs. 47.4 pg/mL, p = 0.009), a trend that lost significance after age and race adjustment (41.7 pg/mL, p = 0.12). Conclusions Compared to healthy controls, adolescents with AN had a lower prevalence of vitamin D deficiency and PTH concentration. However, 25OHD and PTH concentrations were similar after adjustment for race and age. The trend of lower PTH levels in adolescents with AN, accompanied by exceptional compliance with supplementation, may have bone health implications for these patients. Research Support: Funded by NIH Grants RO1 HD043869 and MO1-RR-2172 to the Children’s Hospital General Clinical Research Center; Department of Defense (US Army, Bone Health and Military Readiness); and Project S-T71-MC-0000-10-S1-R0 from the Maternal and Child Health Bureau.     

Vitamin D deficiency in northern Vietnam: Prevalence,risk factors and associations with bone mineral density

PurposeVitamin D deficiency has been linked to osteoporosis and also to the risk of cancer, autoimmune disorders and cardiovascular diseases. This study sought to determine the prevalence of, and risk factors for, vitamin D deficiency and its relationship with bone mineral density (BMD) in a Vietnamese population.MethodsThis cross-sectional study involved 269 women and 222 men aged 13–83 years, who were randomly selected from urban and rural areas in northern Vietnam. Serum concentrations of 25-hydroxy-vitamin D [25(OH)D] and parathyroid hormone (PTH) were measured by electrochemiluminescence immunoassay. Vitamin D deficiency was defined as serum 25(OH)D levels below 20 ng/mL. BMD was measured by dual X-ray absorptiometry.ResultsThe prevalence of vitamin D deficiency in women was 30%, almost two-fold higher than in men (16%). Significant predictors of vitamin D deficiency in women were urban residency (p < 0.01) and age less than 30 years (p < 0.01), whereas use of contraceptive pills was protective (p < 0.01). In men, winter season was the only significant predictor of vitamin D deficiency (p < 0.01). In multiple linear regression analysis, serum levels of 25(OH)D were positively associated with BMD in both women (p < 0.001) and men (p < 0.001).ConclusionsThese data suggest that the prevalence of vitamin D deficiency is high in the Vietnamese population, and that part of this prevalence could be explained by low exposure to sunlight (urban residency and winter season). The high prevalence of vitamin D deficiency should raise the awareness of potentially important health issues such as osteoporosis within the Vietnamese society.     

Utilization of Preoperative Patient Factors to Predict Postoperative Vitamin D Deficiency for Patients Undergoing Gastric Bypass

Introduction  Vitamin D deficiency occurring after gastric bypass procedures can predispose patients to calcium and parathyroid hormone (PTH) level abnormalities. The aim of the study is to identify preoperative patient risk factors for postoperative vitamin D deficiency. Methods  We retrospectively reviewed patients who underwent Roux-en-Y gastric bypass procedures between 2005 and 2006. Patient demographics, laboratory values of calcium, vitamin D, and PTH were followed at quarterly intervals for 1 year. Results  One hundred forty-five patients were included in the study. The mean age for the group was 44 years with an average body mass index of 49.5 kg/m². Eighty-six percent of patients were female and 23% was African–American. Forty-two percent of the patients had vitamin D deficiency (<20 ng/mL) either preoperatively or at year 1. The mean calcium levels decreased from 9.39 to 9.16 mg/dL (p < 0.001) while the mean PTH levels increased from 25.7 to 43.9 ng/mL (p < 0.001). A logistic regression model recognized preoperative vitamin D levels, race, and bypass limb length to be the only significant factors (p < 0.05) for postoperative vitamin D deficiency. Conclusion  It is important to recognize patients who are at risk for vitamin D deficiency before surgery so that early intervention could be in place to minimize further postoperative deficiency. This paper had been presented as a poster at the DDW meeting May 2008, San Diego, CA, USA.     

Vitamin D deficiency in northern Vietnam: Prevalence,risk factors and associations with bone mineral density

PurposeVitamin D deficiency has been linked to osteoporosis and also to the risk of cancer, autoimmune disorders and cardiovascular diseases. This study sought to determine the prevalence of, and risk factors for, vitamin D deficiency and its relationship with bone mineral density (BMD) in a Vietnamese population.MethodsThis cross-sectional study involved 269 women and 222 men aged 13–83 years, who were randomly selected from urban and rural areas in northern Vietnam. Serum concentrations of 25-hydroxy-vitamin D [25(OH)D] and parathyroid hormone (PTH) were measured by electrochemiluminescence immunoassay. Vitamin D deficiency was defined as serum 25(OH)D levels below 20 ng/mL. BMD was measured by dual X-ray absorptiometry.ResultsThe prevalence of vitamin D deficiency in women was 30%, almost two-fold higher than in men (16%). Significant predictors of vitamin D deficiency in women were urban residency (p < 0.01) and age less than 30 years (p < 0.01), whereas use of contraceptive pills was protective (p < 0.01). In men, winter season was the only significant predictor of vitamin D deficiency (p < 0.01). In multiple linear regression analysis, serum levels of 25(OH)D were positively associated with BMD in both women (p < 0.001) and men (p < 0.001).ConclusionsThese data suggest that the prevalence of vitamin D deficiency is high in the Vietnamese population, and that part of this prevalence could be explained by low exposure to sunlight (urban residency and winter season). The high prevalence of vitamin D deficiency should raise the awareness of potentially important health issues such as osteoporosis within the Vietnamese society.     

25-hydroxy vitamin D levels in healthy premenopausal women: Association with bone turnover markers and bone mineral density

BackgroundVitamin D deficiency is very common in elderly people while there are very few reports on its incidence, determinants and metabolic consequences in young subjects.ResultsIn 608 young healthy premenopausal women participating in the BONTURNO study, levels of 25-hydroxyvitamin D [25(OH)D] below 20 ng/ml were found in almost a third of the women. Its levels were inversely (P < 0.001) related with age and body mass index (BMI kg/m²) and directly with sunlight exposure during the summer time, and latitude: i.e. the higher the latitude over Italy, the higher the 25(OH)D level. In women on contraceptive pill the mean 25(OH)D level was significantly increased even when the data were adjusted for age, BMI and sun exposure.25(OH)D levels, adjusted for age and BMI, were significantly and positively related with serum C-telopeptide of type 1 collagen, serum phosphate and spine bone mineral density (BMD) and negatively with serum PTH, serum magnesium, serum bone alkaline phosphatase (bone AP).ConclusionVitamin D deficiency is rather common in young otherwise healthy Italian women and particularly among those living in the Southern part of the country. The most close determinants of vitamin D deficiency were BMI and sunlight exposure. Vitamin D insufficiency is associated with low spine BMD and increased bone AP even in young individuals.     

Effect of vitamin D3 treatment on bone density in neurofibromatosis 1 patients: A retrospective clinical study

ObjectivesWe have previously demonstrated reduced bone density and an increased incidence of 25-hydroxy vitamin D₃ (25-OH D₃) deficiency in adults with neurofibromatosis 1 (NF1) compared to healthy controls. Vitamin D₃ is a cheap, safe, and effective supplement in the general population, but its value in NF1 patients has not been demonstrated. This study investigates the therapeutic potential of oral vitamin D₃ on bone mineral density (BMD) in NF1 patients with vitamin D₃ deficiency.MethodsWe measured serum 25-OH D₃, parathyroid hormone, calcium, and bone alkaline phosphatase concentrations, urinary deoxypyridinoline concentrations, and BMD in 35 adults with NF1. Nineteen patients received vitamin D₃ supplementation for 2 years, six patients received supplementation for 1 year and 10 patients received no supplementation. Supplementation was administered in a dose that maintained the serum 25-OH D₃ level above 30 μg/l. BMD was measured again at 1 and 2 years, and biochemical assessments of bone metabolism were measured at least every half year during therapy.ResultsTreated subjects had significantly reduced loss of BMD, as measured by T score at the hip (p = 0.011) and lumbar spine (p = 0.022). The effect on hip BMD was apparent at 1 year in comparison to baseline (p = 0.02) and was greater at 2 years in comparison to measurements at 1 year (p = 0.02).ConclusionsVitamin D₃ supplementation improves BMD in adult NF1 patients. Further studies are needed to elucidate the mechanisms responsible for reduced BMD in NF1 patients.     

Serum 25-hydroxyvitamin D levels in vitamin D-insufficient hip fracture patients after supplementation with ergocalciferol and cholecalciferol

Vitamin D insufficiency is commonly associated with hip fracture. However, the equipotency of ergocalciferol and cholecalciferol supplementation in this patient group has not been studied in a randomized trial using high-performance liquid chromatography (HPLC) measurement of serum 25-hydroxyvitamin D (25OHD). The objective of this study was to determine if ergocalciferol and cholecalciferol are equipotent therapies in vitamin D-insufficient hip fracture patients.Ninety five hip fracture inpatients with vitamin D insufficiency (25OHD < 50 nmol/L) were randomized, double-blind, to treatment with ergocalciferol 1000 IU/day (n = 48) or cholecalciferol 1000 IU/day (n = 47) for three months. All participants were also given a placebo matching the alternative treatment to maintain blinding of treatment allocation. The primary endpoint was total serum 25OHD measured by HPLC. Secondary endpoints included 25OHD measured by radioimmunoassay (RIA), intact parathyroid hormone (iPTH), and bioactive (1–84) whole PTH (wPTH).Seventy patients (74%) completed the study with paired samples for analysis. Cholecalciferol supplementation resulted in a 31% greater increase in total HPLC-measured 25OHD (p = 0.010) and 52% greater rise in RIA-measured 25OHD (p < 0.001) than supplementation with an equivalent dose of ergocalciferol. Changes in iPTH and wPTH were not significantly different between calciferol treatments (p > 0.05).In vitamin D-insufficient hip fracture patients, supplementation with cholecalciferol 1000 IU/day for three months was more effective in increasing serum 25OHD than an equivalent dose of ergocalciferol. However, the lack of difference in PTH lowering between calciferol treatments raises questions about the biological importance of this observation.     

Vitamin D deficiency in HIV-infected postmenopausal Hispanic and African-American women

Summary

We evaluated vitamin D status in HIV+ and HIV? postmenopausal African-American (AA) and Hispanic women. Most women (74-78%) had insufficient 25-hydroxyvitamin D (25OHD) levels, regardless of HIV status. 25OHD was lower in AA women and women lacking supplement use, providing support for screening and supplementation. Among HIV+ women, 25OHD was associated with current CD4 but not type of antiretroviral therapy.

Introduction

To evaluate vitamin D status and factors associated with vitamin D deficiency and insufficiency in HIV-infected (HIV+) postmenopausal minority women.

Methods

In this cross-sectional study, 89 HIV+ and 95 HIV? postmenopausal women (33% AA and 67% Hispanic) underwent assessment of 25OHD, 1,25-dihydroxyvitamin D, parathyroid hormone, markers of bone turnover and bone mineral density by dual energy X-ray absorptiometry.

Results

The prevalence of low 25OHD did not differ by HIV status; the majority of both HIV+ and HIV? women (74-78%) had insufficient levels (<30?ng/ml). Regardless of HIV status, 25OHD was significantly lower in AA subjects, and higher in subjects who used both calcium and multivitamins. In HIV+ women on antiretroviral therapy (ART), 25OHD was directly associated with current CD4 count (r?=?0.32; p?<?0.01) independent of age, ethnicity, BMI, or history of AIDS-defining illness. No association was observed between 1,25(OH)₂D and CD4 count or between serum 25OHD, 1,25(OH)₂D or PTH and type of ART.

Conclusions

In postmenopausal minority women, vitamin D deficiency was highly prevalent and associated with AA race and lack of supplement use, as well as lower current CD4 cell count. These results provide support for screening and repletion of vitamin D in HIV+ patients.