Vitamin D receptor polymorphisms and nutritional rickets in Nigerian children.

Nutritional rickets is common in Nigeria where vitamin D deficiency is rare and dietary insufficiency of calcium is common. It occurs more commonly in siblings of affected children than of unaffected children. Postulating that vitamin D receptor (VDR) polymorphisms might relate to the susceptibility of some Nigerian children to develop rickets in the setting of low calcium intake, we compared the VDR genotypes, as determined by the presence or absence of Bsm I, Apa I, Taq I, and Fok I restriction enzyme cleavage sites, between 105 children with active nutritional rickets and 94 subjects representative of the community from which the rachitic children came. In the rickets group, the ff genotype was less common than in the community group, and the FF genotype was relatively increased (f allele frequency, 17% in rachitic children and 26% in the community group, p = 0.03). Neither individual allele frequencies for the other polymorphisms nor combinations of genotypes at different sites were different between the rachitic and community groups. Although it is not clear why a presumed better-functioning VDR variant (F allele) is associated with an increased risk of developing rickets, this study raises the possibility that VDR alleles might be important in determining an individual's susceptibility to developing rickets when faced with dietary calcium deficiency.     

Optimal Dose of Calcium for Treatment of Nutritional Rickets: A Randomized Controlled Trial

Calcium supplementation is indicated for the treatment of nutritional rickets. Our aim was to determine the optimal dose of calcium for treatment of children with rickets. Sixty‐five Nigerian children with radiographically confirmed rickets were randomized to daily supplemental calcium intake of 500 mg (n = 21), 1000 mg (n = 23), or 2000 mg (n = 21). Venous blood, radiographs, and forearm areal bone density (aBMD) were obtained at baseline and at 8, 16, and 24 weeks after enrollment. The primary outcome was radiographic healing, using a 10‐point radiographic severity score. The radiographic severity scores improved in all three groups, but the rate of radiographic healing (points per month) was significantly more rapid in the 1000‐mg (–0.29; 95% confidence interval [CI] –0.13 to –0.45) and 2000‐mg (–0.36; 95% CI –0.19 to –0.53) supplementation groups relative to the 500‐mg group. The 2000‐mg group did not heal more rapidly than the 1000‐mg group. Of those who completed treatment for 24 weeks, 12 (67%), 20 (87%), and 14 (67%) in the 2000‐mg, 1000‐mg, and 500‐mg groups, respectively, had achieved a radiographic score of 1.5 or less (p = 0.21). Serum alkaline phosphatase decreased and calcium increased similarly in all groups. Forearm diaphyseal aBMD improved significantly more rapidly in the 2000‐mg group than in the 500‐mg and 1000‐mg groups (p < 0.001). Daily calcium intakes of 1000 mg or 2000 mg produced more rapid radiographic healing of rickets than 500 mg, but 2000 mg did not have greater benefit than 1000 mg. Some children require longer than 24 weeks for complete healing of nutritional rickets. © 2016 American Society for Bone and Mineral Research.     

Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women.

Dietary supplementation with vitamin K(1), with vitamin D(3) and calcium or their combination, was examined in healthy older women during a 2-year, double-blind, placebo-controlled trial. Combined vitamin K with vitamin D plus calcium was associated with a modest but significant increase in BMC at the ultradistal radius but not at other sites in the hip or radius. INTRODUCTION: The putative beneficial role of high dietary vitamin K(1) (phylloquinone) on BMD and the possibility of interactive benefits with vitamin D were studied in a 2-year double-blind, placebo-controlled trial in healthy Scottish women > or =60 years of age. MATERIALS AND METHODS: Healthy, nonosteoporotic women (n = 244) were randomized to receive either (1) placebo, (2) 200 microg/day vitamin K(1), (3) 10 microg (400 IU) vitamin D(3) plus 1000 mg calcium/day, or (4) combined vitamins K(1) and D(3) plus calcium. Baseline and 6-month measurements included DXA bone mineral scans of the hip and wrist, markers of bone turnover, and vitamin status. Supplementation effects were tested using multivariate general linear modeling, with full adjustment for baseline and potential confounding variables. RESULTS: Significant bone mineral loss was seen only at the mid-distal radius but with no significant difference between groups. However, women who took combined vitamin K and vitamin D plus calcium showed a significant and sustained increase in both BMD and BMC at the site of the ultradistal radius. Serum status indicators responded significantly to respective supplementation with vitamins K and D. Over 2 years, serum vitamin K(1) increased by 157% (p < 0.001), the percentage of undercarboxylated osteocalcin (%GluOC) decreased by 51% (p < 0.001), serum 25-hydroxyvitamin D [25(OH)D] increased by 17% (p < 0.001), and PTH decreased by 11% (p = 0.049). CONCLUSIONS: These results provide evidence of a modest synergy in healthy older women from nutritionally relevant intakes of vitamin K(1) together with supplements of calcium plus moderate vitamin D(3) to enhance BMC at the ultradistal radius, a site consisting of principally trabecular bone. The substantial increase in gamma-carboxylation of osteocalcin by vitamin K may have long-term benefits and is potentially achievable by increased dietary intakes of vitamin K rather than by supplementation.     

Bone mineral analysis and X-ray examination of the bone in patients with biliary atresia

Investigations of bone mineral content, X-ray of the radius and ulna and serum biochemical analysis were performed in 10 children with biliary atresia (B.A.) and 150 healthy children. The patients were classified into 2 groups, namely; group A, comprised of 5 patients whose postoperative courses went well, and group B, comprised of 5 patients who developed various degrees of liver disturbance postoperatively. The ratio of bone mineral content (BMC) to bone width (BW) (BMC/BW) increased in accordance with age in the healthy children and the patients of group A, but was relatively slow in the patients of group B. Sings of rickets were found on the X-rays of 4 of the 10 patients, while serum levels of calcium and 25-OH-vitamin D in the group B patients were significantly lower than those in the group A patients or healthy children. Serum levels of alkaline phosphatase (Alp) fluctuated, but serum Alp was elevated in all the patients with rickets.     

Bone mineral analysis and X-ray examination of the bone in patients with biliary atresia

Investigations of bone mineral content, X-ray of the radius and ulna and serum biochemical analysis were performed in 10 children with biliary atresia (B.A.) and 150 healthy children. The patients were classified into 2 groups, namely; group A, comprised of 5 patients whose postoperative courses went well, and group B, comprised of 5 patients who developed various degrees of liver disturbance postoperatively. The ratio of bone mineral content (BMC) to bone width (BW) (BMC/BW) increased in accordance with age in the healthy children and the patients of group A, but was relatively slow in the patients of group B. Signs of rickets were found on the X-rays of 4 of the 10 patients, while serum levels of calcium and 25-OH-vitamin D in the group B patients were significantly lower than those in the group A patients or healthy children. Serum levels of alkaline phosphatase (Alp) fluctuated, but serum Alp was elevated in all the patients with rickets.     

Calcium and vitamin-D supplementation on bone structural properties in peripubertal female identical twins: a randomised controlled trial

Summary

A randomised controlled trial was used in assessing the impact of 6?months of daily calcium and vitamin-D supplementation on trabecular and cortical bone acquisition at distal tibial and radial sites using peripheral quantitative computed tomography (pQCT). Daily supplementation was associated with increased bone density and bone strength at the distal tibia and radius.

Introduction

pQCT has not been used to assess bone responses to calcium and vitamin-D supplementation on peripubertal children. This randomised controlled trial aimed to assess the impact of a 6-month daily calcium and vitamin-D supplementation on trabecular and cortical bone acquisition at distal tibial and radial sites using pQCT.

Methods

Twenty pairs of peripubertal female identical twins, aged 9 to 13?years, were randomly assigned to receive either 800?mg of calcium and 400?IU of vitamin D3, or a matched placebo. Bone structural properties at the distal tibia and distal radius were acquired at baseline and 6?months.

Results

The calcium-supplemented group showed greater gains in trabecular density, trabecular area and strength strain index at the 4% of distal tibial and radial sites compared with the placebo group (p?=?0.001). Greater gains in cortical area at the 38% and 66% of tibial sites were also found in twins receiving the calcium supplement (p?=?0.001).

Conclusions

Daily supplementation for a period of 6?months was associated with increased trabecular area, trabecular density and strength strain index at the ultra-distal tibia and radius and increased cortical area at tibial mid-shaft.     

Calcium- and vitamin D3-fortified milk reduces bone loss at clinically relevant skeletal sites in older men: a 2-year randomized controlled trial.

In this 2-year randomized controlled study of 167 men >50 years of age, supplementation with calcium-vitamin D3-fortified milk providing an additional 1000 mg of calcium and 800 IU of vitamin D3 per day was effective for suppressing PTH and stopping or slowing bone loss at several clinically important skeletal sites at risk for fracture. INTRODUCTION: Low dietary calcium and inadequate vitamin D stores have long been implicated in age-related bone loss and osteoporosis. The aim of this study was to assess the effects of calcium and vitamin D3 fortified milk on BMD in community living men >50 years of age. MATERIALS AND METHODS: This was a 2-year randomized controlled study in which 167 men (mean age +/- SD, 61.9 +/- 7.7 years) were assigned to receive either 400 ml/day of reduced fat ( approximately 1%) ultra-high temperature (UHT) milk containing 1000 mg of calcium plus 800 IU of vitamin D3 or to a control group receiving no additional milk. Primary endpoints were changes in BMD, serum 25(OH)D, and PTH. RESULTS: One hundred forty-nine men completed the study. Baseline characteristics between the groups were not different; mean dietary calcium and serum 25(OH)D levels were 941 +/- 387 mg/day and 77 +/- 23 nM, respectively. After 2 years, the mean percent change in BMD was 0.9-1.6% less in the milk supplementation compared with control group at the femoral neck, total hip, and ultradistal radius (range, p < 0.08 to p < 0.001 after adjusting for covariates). There was a greater increase in lumbar spine BMD in the milk supplementation group after 12 and 18 months (0.8-1.0%, p < or = 0.05), but the between-group difference was not significant after 2 years (0.7%; 95% CI, -0.3, 1.7). Serum 25(OH)D increased and PTH decreased in the milk supplementation relative to control group after the first year (31% and -18%, respectively; both p < 0.001), and these differences remained after 2 years. Body weight remained unchanged in both groups at the completion of the study. CONCLUSIONS: Supplementing the diet of men >50 years of age with reduced-fat calcium- and vitamin D3-enriched milk may represent a simple, nutritionally sound and cost-effective strategy to reduce age-related bone loss at several skeletal sites at risk for fracture in the elderly.     

Comparison of metabolism of vitamins D2 and D3 in children with nutritional rickets

Children with calcium‐deficiency rickets may have increased vitamin D requirements and respond differently to vitamin D₂ and vitamin D₃. Our objective was to compare the metabolism of vitamins D₂ and D₃ in rachitic and control children. We administered an oral single dose of vitamin D₂ or D₃ of 1.25 mg to 49 Nigerian children—28 with active rickets and 21 healthy controls. The primary outcome measure was the incremental change in vitamin D metabolites. Baseline serum 25‐hydroxyvitamin D [25(OH)D] concentrations ranged from 7 to 24 and 15 to 34 ng/mL in rachitic and control children, respectively (p < .001), whereas baseline 1,25‐dihydroxyvitamin D [1,25(OH)₂D] values (mean ± SD) were 224 ± 72 and 121 ± 34 pg/mL, respectively (p < .001), and baseline 24,25‐dihydroxyvitamin D [24,25(OH)₂D] values were 1.13 ± 0.59 and 4.03 ± 1.33 ng/mL, respectively (p < .001). The peak increment in 25(OH)D was on day 3 and was similar with vitamins D₂ and D₃ in children with rickets (29 ± 17 and 25 ± 11 ng/mL, respectively) and in control children (33 ± 13 and 31 ± 16 ng/mL, respectively). 1,25(OH)₂D rose significantly (p < .001) and similarly (p = .18) on day 3 by 166 ± 80 and 209 ± 83 pg/mL after vitamin D₂ and D₃ administration, respectively, in children with rickets. By contrast, control children had no significant increase in 1,25(OH)₂D (19 ± 28 and 16 ± 38 pg/mL after vitamin D₂ and D₃ administration, respectively). We conclude that in the short term, vitamins D₂ and D₃ similarly increase serum 25(OH)D concentrations in rachitic and healthy children. A marked increase in 1,25(OH)₂D in response to vitamin D distinguishes children with putative dietary calcium‐deficiency rickets from healthy children, consistent with increased vitamin D requirements in children with calcium‐deficiency rickets. © 2010 American Society for Bone and Mineral Research     

Effects of a short-term vitamin D and calcium supplementation on body sway and secondary hyperparathyroidism in elderly women.

Long-term vitamin D and calcium supplementation is effective in reducing nonvertebral fractures in elderly people. Increased bone fragility caused by secondary hyperparathyroidism (sHPT) and impaired balance are known risk factors for hip fractures. The hypothesis is that short-term therapy with calcium and vitamin D may improve body sway as well as sHPT more effectively than calcium monotherapy. The effects of 8 weeks of supplementation with vitamin D (cholecalciferol) and calcium on body sway and biochemical measures of bone metabolism were measured. The sample consisted of 148 women (mean [+/-SD] age, 74 +/- 1 years) with a 25-hydroxycholecalciferol level below 50 nmol/liter. They received either 1200 mg of calcium plus 800 IU of vitamin D or 1200 mg of calcium per day. We measured intact parathyroid hormone (PTH), markers of bone turnover, and body sway before and after treatment. Falls and fractures among the participants were followed over a 1-year period. Compared with calcium mono, supplementation with vitamin D and calcium resulted in an increase in serum 25-hydroxyvitamin D of 72% (p < 0.0001), a decrease in the serum PTH of 18% ( p = 0.0432), and a decrease in body sway of 9% (p = 0.0435). The mean number of falls per subject during a 1-year follow-up period was 0.45 for the calcium mono group and 0.24 for the calcium and vitamin D group (p = 0.0346). Short-term supplementation with vitamin D and calcium improves sHPT and body sway and therefore may prevent falls and subsequent nonvertebral fractures in elderly women.     

Inadequate dietary calcium and vitamin D intakes in renal-transplant recipients in Ireland.

OBJECTIVE: To quantify the dietary calcium and vitamin D intake in adult renal-transplant recipients attending at a large teaching hospital in Ireland for follow-up. SETTING: Outpatient renal-transplant follow-up clinic. SUBJECTS: Fifty-nine adult renal transplant recipients (58% male) with a mean age of 46 years, a median transplant duration of 6 years, and a mean estimated glomerular filtration rate (eGFR) of 50 mL/min per 1.73 m2. Fifty-three percent were at National Kidney Foundation stage 3 chronic kidney disease, and 14% had stage 4 chronic kidney disease. INTERVENTION: This cross-sectional, observational study used a tailored food frequency questionnaire specific for calcium and vitamin D intake in Irish adults, which was completed during a face-to-face interview with each subject. MAIN OUTCOME MEASURE: The main outcome measure was the average daily dietary and supplemented calcium and vitamin D intake. RESULTS: The median interquartile range (IQR) dietary calcium intake was 820 mg/day (range, 576-1,177 mg/day), and was similar in men and women (recommended intake > or = 1,000 mg/day in adult men and nonmenopausal adult women, > or = 1,500 mg/day in menopausal women). Five participants received calcium supplementation. Overall, 59% of men and 64% of women had total calcium intakes below the recommended amounts. The median IQR estimated dietary vitamin D intake was 5.2 microg/day (range, 2.4-6.4 microg/day) in women, and 4.6 microg/day (range, 2.2-6.6 microg/day) in men (recommended intake, > or = 10 microg/day). Six subjects received vitamin D supplementation. Total vitamin D intakes were suboptimal in 91% of men and 87% of women. Dietary calcium and vitamin D intakes significantly correlated with each other, but neither was significantly related to eGFR category, and was similarly low in both presumed menopausal women and in the initial year posttransplantation. CONCLUSION: These findings suggest that dietary and total calcium and vitamin D intakes in adult renal-transplant patients are in many cases inadequate.     

Vitamin D and skeletal health in infancy and childhood

During growth, severe vitamin D deficiency in childhood can result in symptomatic hypocalcaemia and rickets. Despite the suggestion from some studies of a secular increase in the incidence of rickets, this observation may be driven more by changes in population demographics than a true alteration to age, sex and ethnicity-specific incidence rates; indeed, rickets remains uncommon overall and is rarely seen in fair-skinned children. Additionally, the impact of less severe vitamin D deficiency and insufficiency has received much interest in recent years, and in this review, we consider the evidence relating vitamin D status to fracture risk and bone mineral density (BMD) in childhood and adolescence. We conclude that there is insufficient evidence to support the suggestion that low serum 25-hydroxyvitamin D [25(OH)D] increases childhood fracture risk. Overall, the relationship between 25(OH)D and BMD is inconsistent across studies and across skeletal sites within the same study; however, there is evidence to suggest that vitamin D supplementation in children with the lowest levels of 25(OH)D might improve BMD. High-quality randomised trials are now required to confirm this benefit.     

High impact exercise is more beneficial than dietary calcium for building bone strength in the growing rat skeleton

The benefits of impact exercise and dietary calcium on bone development are controversial. We used inbred rats under highly controlled conditions to test the independent and combined effects of impact exercise and physiological levels of calcium intakes on the growing skeleton. Forty growing F-344 female rats were fed diets containing either 100% (Ca+; 0.5% Ca) or 40% (Ca(-); 0.2% Ca) of their calcium requirements. Half of each dietary group was subjected to either 10 impacts per day from 45 cm freefall drops (Impact+), or no impact (Impact(-)). All rats received a free choice of physical activity period daily. After 8 weeks, the mechanical strength, volumetric density, geometry, and microarchitecture of their ulnae were measured. Body weight and bone length did not differ among groups. On both diets, freefall impact resulted in greater bone strength, cross-sectional moments of inertia, and endosteal and periosteal circumferences in the shaft. Only Ca+ resulted in greater shaft volumetric bone mineral density (vBMD) but that did not affect shaft breaking strength. In the bone ends, both Impact+ and Ca+ positively affected density and structure of both cortical and trabecular bone but the effects of Impact+ were more pervasive. In the proximal end, Impact+ resulted in greater bone volume fraction (BV/TV) in the trabecular bone due to greater trabecular thickness, and cortical thickness was greater due to a smaller endosteal circumference. Impact+ exerted a compensatory effect on vBMD and BV/TV in Ca(-) rats at the proximal site. In Impact(-) rats only, Ca+ resulted in greater total and cortical vBMD and BV/TV in the proximal ulna. Impact+ and Ca+ exerted additive effects on cortical bone area (BA) in the proximal ulna and on total BA, periosteal circumference, and trabecular vBMD in the distal ulna. In conclusion, impact exercise was more beneficial than adequate dietary calcium to growing bones, although sufficient dietary calcium was beneficial in rats not subjected to impact exercise.     

Effect of Calcium and Vitamin D Supplementation With and Without Collagen Peptides on Volumetric and Areal Bone Mineral Density,Bone Geometry and Bone Turnover in Postmenopausal Women With Osteopenia

Collagen peptides (CPs) have been shown to potentially have a role as a treatment option in osteopenia. In the present randomized prospective study, we examined the effect of calcium, vitamin D with and without CPs supplementation on changes in volumetric bone mineral density (vBMD) and bone geometry assessed by peripheral quantitative computed tomography at the tibia, areal bone mineral density (aBMD) assessed by dual-energy X-ray absorptiometry at the lumbar spine and the hip and bone turnover markers over 12-mo. Fifty-one postmenopausal women with osteopenia were allocated to Group A who received orally 5 g CPs, 500 mg calcium and 400 IU vitamin D3 and Group B who received the same dose of calcium and vitamin D3 per day. The primary endpoint was the change of trabecular bone mineral content (BMC) and vBMD after 12-mo supplementation in Groups A and B. At the trabecular site (4% of the tibia length), Group A had a significant increase of total BMC by 1.96 ± 2.41% and cross-sectional area by 2.58 ± 3.91%, trabecular BMC by 5.24 ± 6.48%, cross-sectional area by 2.58 ± 3.91% and vBMD by 2.54 ± 3.43% and a higher % change of these parameters at 12 mo in comparison to Group B (p < 0.01, p = 0.04, p < 0.01, p = 0.04, p = 0.02, respectively). At the cortical site (38% of the tibia length), total and cortical vBMD increased by 1.01 ± 2.57% and 0.67 ± 1.71%. Furthermore, the mean aBMD at the spine was higher (p = 0.01), while bone markers decreased in Group A compared to Group B. The present study shows improvement of trabecular and cortical parameters as assessed by peripheral quantitative computed tomography at the tibia, prevention of aBMD decline and decrease of bone turnover after 12-mo supplementation with calcium, vitamin D with CPs.     

An investigation of calcium intake, 1-alpha(OH)D3, and etidronate on bone

The synthetic metabolite of vitamin D3 [1 alpha(OH)D3] caused a significant plasma calcium elevation in rats only when dietary calcium was low. Animals given the low calcium diet (0.005%) had lower plasma parathyroid hormone (PTH) levels when the diet contained 1 alpha(OH)D3 and significantly higher levels than animals on a high calcium (0.95%) diet, with or without the vitamin. The nutritional stress of a low calcium diet without 1 alpha(OH)D3 resulted in a prolonged severe hypocalcemia and elevated serum PTH levels. A higher ash, phosphate, and calcium content was found in the bones of animals fed the high calcium diet, with no vitamin D3 that were given etidronate (EHDP). When animals received the same calcium diet with 1 alpha(OH)D3 supplementation, EHDP administration increased the percentage of bone ash but had no effect on ash weight. 1 alpha(OH)D3 or EHDP did not affect ash weight, dry fat free weight, and percentage of ash of bone of animals receiving a low calcium diet. The percentage of calcium and phosphorus in bone ash was similar among all groups, although the amounts per humerus were characteristically related to the calcium intake. There was approximately 20-25% less bone mineral and calcium and phosphorus in the humeri of low calcium intake animals than in animals provided an adequate dietary calcium.     

Calcium supplementation and weight bearing physical activity--do they have a combined effect on the bone density of pre-pubertal children?

The adaptation of bone to exercise has been shown to be modified by dietary calcium intake. The aim of this randomised controlled trial was to investigate whether there was a differential response to calcium supplementation in elite gymnasts and school children controls. The primary hypothesis was that gymnasts who took calcium supplements would have greater increases in cortical and trabecular volumetric bone mineral density (vBMD) at the radius and tibia. Secondary outcomes studied were changes in bone geometry at the radius and tibia and lumbar spine and whole body measurements. Children were randomised to 12 months daily supplementation of 500 mg elemental calcium (1250 mg (in the form of calcium carbonate salt)) or placebo. Outcome measures were assessed using peripheral quantitative computed tomography (pQCT) (distal and diaphyseal radius and tibia) and dual energy X-ray absorptiometry (DXA) (lumbar spine and whole body). Eighty-six subjects participated in the trial (44 gymnasts, 42 controls) and 75 subjects completed the trial (39 gymnasts, 36 controls). Data were analysed by analysis of covariance adjusting for baseline value of bone parameters, age, height, gender and puberty, and delay between baseline measurement and start of intervention. The primary analysis was for a calcium-exercise interaction; a pooled calcium effect with no interaction was also tested. Results are presented as ratios (95% confidence intervals). At the distal tibia, trabecular vBMD showed a significant interaction (p=0.04), with controls (1.00: 0.99, 1.09) responding more than gymnasts (0.98: 0.94, 1.02) to supplementation. At the distal radius, change in trabecular vBMD was not significant (p=0.05). There were no differences in change in cortical vBMD at either site between the gymnasts and controls (tibia: p=0.82, radius: p=0.88). For all other secondary outcomes at radius, tibia, spine and whole body no significant interactions were found. In conclusion, there was no beneficial effect of additional calcium in gymnasts who already consume their recommended nutrient intake (888 mg/day; United Kingdom reference nutrient intake for 8- to 11-year-olds is 555-800 mg/day) for calcium. We speculate that gymnasts have already adapted their bones (geometry and vBMD) to the demands imposed upon them by the loading they are subjected to during gymnastics and do not benefit from additional calcium supplementation.     

Effect on bone density of postoperative calcium and vitamin-D supplementation in patients with primary hyperparathyroidism: A retrospective study

Background  Primary hyperparathyroidism (pHPT) is associated with decreased bone density and increased fracture risk. A significant number of pHPT patients have low calcium intake and suffer from vitamin deficiency. Thus, we adopted a policy of postoperative supplements with calcium and vitamin D after parathyroid surgery. In this study, we investigated if this policy enhanced the postoperative increase in bone density. Patients/Methods  Forty-two consecutive patients (83% female) were studied. The first 21 patients received no supplements, whereas the following 21 patients received 1,000 g calcium and 800 IU hydroxy D-vitamin daily (Ca–D group) for 1 year postoperatively. The patients were monitored with bone density and biochemistry pre- and at 1 year postoperatively. Results  Preoperatively, the patients without vitamin D supplementation (non-Ca–D group) did neither differ in biochemistry, clinical features, nor in bone density from patients in Ca–D group. Postoperatively, there was a tendency that patients in Ca–D group increased their bone density, at all sites measured, in a greater extent than patients that did not receive calcium and vitamin D supplementation. Conclusion  In conclusion, based on our results, it is difficult to give a recommendation of vitamin D supplementation in routine use following surgery for primary hyperparathyroidism. Based on the present data, a calculation of sample size for a future randomized controlled trial is presented.     

Evidence that Treatment with Risedronate in Women with Postmenopausal Osteoporosis Affects Bone Mineralization and Bone Volume

Risedronate is used in osteoporosis treatment. Postmenopausal women enrolled in the Vertebral Efficacy with Risedronate Therapy trial received either risedronate (5 mg/day) or placebo for 3 years. Subjects received calcium and vitamin D supplementation if deficient at baseline. Lumbar spine bone mineral density (BMD) was measured at baseline and at 3 years. Quantitative back-scattered electron imaging (qBEI) was performed on paired iliac crest biopsies (risedronate, n = 18; placebo, n = 13) before and after treatment, and the mineral volume fraction in the trabecular bone was calculated. Combining dual-energy X-ray absorptiometric values with the mineral volume fraction for the same patients allowed us to calculate the relative change in trabecular bone volume with treatment. This showed that the effect on BMD was likely to be due partly to changes in matrix mineralization and partly due to changes in bone volume. After treatment, trabecular bone volume in the lumbar spine tended to increase in the risedronate group (+2.4%, nonsignificant) but there was a significant decrease (−3.7%, P < 0.05) in the placebo group. Calcium supplementation with adequate levels of vitamin D led to an ∼3.3% increase in mineral content in the bone material independently of risedronate treatment. This increase was larger in patients with lower matrix mineralization at baseline and likely resulted from correction of calcium/vitamin D deficiency as well as from reduced bone remodeling. Combining BMD and bone mineralization density distribution data show that in postmenopausal osteoporosis 3-year treatment with risedronate preserves or may increase trabecular bone volume, unlike placebo. This analysis also allows, for the first time, separation of the contributions of bone volume and matrix mineralization to the increase in BMD.     

Prevalence of vitamin D insufficiency in postmenopausal south Indian women

Aim: To evaluate the dietary calcium and vitamin D status in south Indian postmenopausal women. Methods: Postmenopausal women (n=164) were evaluated for their daily dietary calcium intake, phytate to calcium ratio, and bone mineral parameters. Their serum leutinizing hormone (LH), follicle-stimulating hormone (FSH), 25-hydroxyvitamin D (25[OH]D), and parathyroid hormone levels (PTH) were measured. Results: Their age and BMI were 59.5 ± 8 years and 27 ± 5 kg/m², respectively. Their daily dietary intake of calcium was 323 ± 66 mg/day; phytate to calcium ratio, 0.56±0.1; LH, 26 ± 13.5 µIU/l; and FSH, 62.6 ± 30 µIU/l. Their dietary intake of calcium was low compared with the recommended daily/dietary allowance (RDA) of the Indian Council of Medical Research (ICMR) for the Indian population. Of the 164 patients studied, based on population-based reference values, 126 (77%) had normal 25(OH)D levels (9–37.6 ng/ml), and 38 (23%) had 25(OH)D deficiency. Using functional health-based reference values, 30 (18%) patients had normal 25(OH)D levels (>20 ng/ml), 85 (52%) had 25(OH)D insufficiency (10–20 ng/ml), and 49(30%) had 25(OH)D deficiency (<10 ng/ml). PTH and serum alkaline phosphatase (SAP) was significantly high in patients with 25(OH)D deficiency (p<0.05) compared with those with normal 25(OH)D levels. There was a negative correlation between 25(OH)D and PTH (r=–0.2; p<0.007) and SAP (r=–0.2; p<0.001). Dietary calcium correlated positively with dietary phosphates (r=0.8; p<0.001) and phytate to calcium ratio (r=0.75; p<0.001). Conclusions: Population-based reference values underdiagnosed vitamin D insufficiency and overdiagnosed normal vitamin D status. The diet was insufficient in calcium and high in phytate. About 82% of the study group had varying degrees of low 25-hydroxyvitamin D levels. The quality of diet has to be improved with enrichment/supplementation of calcium and vitamin D to suppress secondary hyperparathyroidism-induced bone loss and risk of fractures.