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Calcium Supplementation (calcium + supplementation)

Distribution by Scientific Domains

Medical Sciences	78%

Selected Abstracts

Calcium supplementation of breeding birds: directions for future research

IBIS, Issue 4 2004
S. James Reynolds
Calcium is an essential nutrient for avian reproduction. Calcium-rich foods are consumed by breeding birds for production of eggshells and for provisioning chicks that are mineralizing skeletal tissues. A number of studies have documented calcium-limited reproduction, and calcium supplementation has been employed over the last decade to demonstrate degrees, causes and consequences of calcium limitation. However, supplementation studies have produced equivocal findings resulting from an absence of calcium limitation in the study species, a poorly designed supplementation procedure or both. Prior to effective calcium supplementation, many factors need to be considered. Calcium-limited breeding in birds can only be detected by monitoring breeding attempts for more than one year and by ensuring that the measured breeding parameters are sensitive to calcium availability. Natural calcium availability needs to be estimated, and daily calcium budgets for the appropriate reproductive stages determined for the study species. Most crucially, if calcium limitation of breeding is caused by secondary calcium limitation (e.g. through heavy metal toxicity), calcium supplementation will probably be ineffective. Effective calcium supplementation will then be achieved through careful planning , a study over several years using appropriate supplements (i.e. naturally occurring ones used by breeding birds), applied at the appropriate time of year (i.e. prelaying and/or chick-rearing phases) and using a response variable that is highly sensitive to calcium availability. If properly planned and performed, calcium supplementation is a cost-effective and potent tool for the study of bird breeding biology. [source]

Effects of calcium supplementation on fetal growth in mothers with deficient calcium intake: a randomised controlled trial

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2010
Edgardo Abalos
Summary Abalos E, Merialdi M, Wojdyla D, Carroli G, Campodónico L, Yao S-E, Gonzalez R, Deter R, Villar J, Van Look P. Effects of calcium supplementation on fetal growth in mothers with deficient calcium intake: a randomised controlled trial. Paediatric and Perinatal Epidemiology 2010; 24: 53,62. Calcium supplementation in mothers with low calcium intake has been of interest recently because of its association with optimal fetal growth and improved pre-eclampsia-related outcomes. While the effects of calcium supplementation have demonstrated benefits in prolonging gestation and subsequently improving birthweight, no specific studies have identified the longitudinal effects of supplementation on fetal growth in utero. Data were analysed in the context of the World Health Organization trial of calcium supplementation in calcium-deficient women. Five hundred and ten healthy, primiparous pregnant Argentinean women were randomised (at <20 weeks gestation) to either placebo (n = 230) or calcium supplements (1500 mg calcium/day in 3 divided doses; n = 231). Growth parameters in utero were assessed with serial ultrasound scans. Birthweight, length, head, abdominal and thigh circumferences were recorded at delivery. No differences were found in fetal biometric measurements recorded at 20, 24, 28, 32 and 36 weeks gestation between fetuses of women who were supplemented with calcium and those who were not. Similarly, neonatal characteristics and anthropometric measurements recorded at delivery were comparable in both groups. We conclude that calcium supplementation of 1500 mg calcium/day in pregnant women with low calcium intake does not appear to impact on fetal somatic or skeletal growth. [source]

A Modified Atkins Diet Is Effective for the Treatment of Intractable Pediatric Epilepsy

EPILEPSIA, Issue 2 2006
Eric H. Kossoff
Summary:,Purpose: The Atkins diet may induce ketosis as does the ketogenic diet, without restrictions on calories, fluids, protein, or need for an inpatient fast and admission. Our objective was to evaluate the efficacy and tolerability of a modified Atkins diet for intractable childhood epilepsy. Methods: Twenty children were treated prospectively in a hospital-based ambulatory clinic from September 2003 to May 2005. Children aged 3,18 years, with at least three seizures per week, who had been treated with at least two anticonvulsants, were enrolled and received the diet over a 6-month period. Carbohydrates were initially limited to 10 g/day, and fats were encouraged. Parents measured urinary ketones semiweekly and recorded seizures daily. All children received vitamin and calcium supplementation. Results: In all children, at least moderate urinary ketosis developed within 4 days (mean, 1.9). Sixteen (80%) completed the 6-month study; 14 chose to remain on the diet afterward. At 6 months, 13 (65%) had >50% improvement, and seven (35%) had >90% improvement (four were seizure free). Mean seizure frequency after 6 months was 40 per week (p = 0.005). Over a 6-month period, mean serum blood urea nitrogen increased from 12 to 17 mg/dl (p = 0.01); creatinine was unchanged. Cholesterol increased from 192 to 221 mg/dl, (p = 0.06). Weight did not change significantly (34.0,33.7 kg); only six children lost weight. A stable body mass index over time correlated with >90% improvement (p = 0.004). Conclusions: A modified Atkins diet is an effective and well-tolerated therapy for intractable pediatric epilepsy. [source]

Calcium supplementation of breeding birds: directions for future research

Oral calcium supplementation associated with decreased likelihood of nephrolithiasis prior to surgery for hyperparathyroidism

INTERNATIONAL JOURNAL OF UROLOGY, Issue 12 2007
Matthew R Cooperberg
Abstract: We aimed to assess the impact of oral calcium supplementation (OCS) on the prevalence of nephrolithiasis among a cohort of patients undergoing surgery for primary hyperparathyroidism (PHPT). There were 339 patients undergoing surgery for PHPT with detailed past medical history data that were analyzed. 73 patients (22%) had a history of nephrolithiasis prior to parathyroid surgery. Nephrolithiasis was more common among men than women (40% vs 15%, P < 0.001), despite the predominance of women (73% of patients) with hyperparathyroidism. 83 patients (25%) used OCS. OCS was associated with a lower prevalence of nephrolithiasis (9.6% vs 25.4% without OCS, P = 0.002). This protective effect included both men and women (rates of nephrolithiasis with and without supplements: men 19% vs 46%, P = 0.027; women 7% vs 17%, P = 0.04). The mechanism for the apparent protective effect of OCS on rates of nephrolithiasis is unclear, and further research is required to elucidate the variable penetrance of nephrolithiasis among PHPT patients. [source]

Effects of calcium supplementation on fetal growth in mothers with deficient calcium intake: a randomised controlled trial

Ultrasonography: Highly Accuracy Technique for Preoperative Localization of Parathyroid Adenoma,

THE LARYNGOSCOPE, Issue 9 2008
Bassam Abboud MD
Abstract Objectives/Hypothesis: This study evaluates the accuracy of ultrasonography in guided unilateral parathyroidectomy to treat primary hyperparathyroidism. Study Design: Retrospective study. Methods: Two hundred fifty-three patients with primary hyperparathyroidism underwent preoperative ultrasonography. Two groups were defined. Group 1 included the patients in whom the preoperative cervical ultrasound localized one abnormal parathyroid gland; these patients underwent unilateral surgical exploration of the neck under local anesthesia. Group 2 included the patients who had a bilateral neck exploration under general anesthesia when the preoperative examination was equivocal or failed to localize the lesion, when concomitant thyroid pathology indicated thyroidectomy, and when justified by the surgical findings. Results: Sensitivity and positive predictive value of ultrasonography in detecting abnormal parathyroid gland were 96% and 98%, respectively. Cervical ultrasound correctly identified, 96% and 85% of abnormal glands in groups 1 and 2, respectively. The presence of thyroid nodular disease did not affect ultrasonographic accuracy. Sonographic examination decreased the operative time of parathyroidectomy to an average of 15 minutes. Mediastinal and retroesophageal localizations of abnormal parathyroid gland adversely affected the accuracy of the ultrasound. No cervical hematoma was noted. Transient recurrent laryngeal nerve palsy occurred in four patients. Twenty-three patients required postoperative calcium supplementation for 2 to 4 months, and all were normocalcemic at follow-up. Conclusions: Cervical ultrasound is a reliable preoperative exploration allowing parathyroidectomy via unilateral approach under local anesthesia. [source]

A Safe and Cost-Effective Short Hospital Stay Protocol to Identify Patients at Low Risk for the Development of Significant Hypocalcemia After Total Thyroidectomy

THE LARYNGOSCOPE, Issue 6 2006
Zayna S. Nahas BS
Abstract Objective: The objective of this retrospective chart review was to determine if serial postoperative serum calcium levels early after total thyroidectomy can be used to develop an algorithm that identifies patients who are unlikely to develop significant hypocalcemia and can be safely discharged within 24 hours after surgery. Methods: Records of 135 consecutive patients who underwent total/completion thyroidectomy and were operated on by the senior author from 2001 to 2005 have been reviewed. For the entire study group, reports of the early postoperative serum calcium levels (6 hours and 12 hours postoperatively), final thyroid pathology, preoperative examination, inpatient course, and postoperative follow up were reviewed. An endocrine medicine consultation was obtained for all patients while in the hospital after surgery. For patients who developed significant hypocalcemia, reports of their management and the need for readmission or permanent medications for hypoparathyroidism were reviewed. According to the change in serum calcium levels between 6 hours and 12 hours postoperatively, patients were divided into two groups: 1) positive slope (increasing) and 2) nonpositive (nonchanging/decreasing). Results: All patients with a positive slope (50/50) did not develop significant hypocalcemia in contrast to only 59 of 85 patients (69.4%) with a nonpositive slope (P < .001, positive predictive value of positive slope in predicting freedom from significant hypocalcemia = 100%, 95% confidence interval = 92.9,100). In the nonpositive slope group, 61 patients had a serum calcium level ,8 mg/dL at 12 hours postoperatively (,0.5 mg/dL below the low end of normal), and 53 (87%) of these patients remained free of significant hypocalcemia in contrast to only 6 (25%) of 24 patients with serum calcium level <8 mg/dL at 12 hours postoperatively (sensitivity = 90%, positive predictive value = 87%). In addition, of the eight patients who developed significant hypocalcemia in the nonpositive slope group with a serum calcium level ,8 mg/dL at 12 hours postoperatively, 7 (88%) patients developed the signs and symptoms during the first 24 hours after total thyroidectomy. Readmission and permanent need for calcium supplementation happened in two patients, respectively, all with serum calcium levels <8 mg/dL at 12 hours after total thyroidectomy. The compressive and/or symptomatic large multinodular goiter as an indication for thyroidectomy was associated with developing significant hypocalcemia (P < .05). There was no statistically significant correlation between the development of significant hypocalcemia and gender, age, thyroid pathology other than goiter, or neck dissection. Conclusion: Patients with a positive serum calcium slope (t = 6 and 12 hours) after total thyroidectomy are safe to discharge within 24 hours after surgery with patient education with or without calcium supplementation. In addition, patients with a nonpositive slope and a serum calcium level ,8 mg/dL at 12 hours postoperatively (,0.5 mg/dL below the low end of normal) are unlikely to develop significant hypocalcemia, especially beyond 24 hours postoperatively, and therefore can be safely discharged within 24 hours after total thyroidectomy with patient education and oral calcium supplementation. Our management algorithm identifies those patients at low risk of developing significant hypocalcemia early in the postoperative course after total thyroidectomy to allow for a short hospital stay and safe discharge. [source]

Safety of Completion Thyroidectomy Following Unilateral Lobectomy for Well-Differentiated Thyroid Cancer,

THE LARYNGOSCOPE, Issue 7 2002
Michael E. Kupferman MD
Abstract Objectives When a diagnosis of thyroid cancer is returned following unilateral lobectomy, removal of the contralateral lobe is frequently necessary. Morbidity for completion thyroidectomy includes a reported 2% to 5% risk of recurrent laryngeal nerve (RLN) injury and an 8% to 15% incidence of hypoparathyroidism. In this study, to determine morbidity following completion thyroidectomy, we reviewed our results of reoperative surgery among patients with thyroid cancer. Study Design Retrospective chart review. Methods Between 1997 and 2000, 36 consecutive patients, 32 females and 4 males, with a mean age of 43.6 years (range, 19,59 y), underwent completion thyroidectomy. Preoperative fine-needle aspiration revealed follicular derived neoplasm in 32 patients (88.9%), indeterminate in 3 patients (8.3%), and Hürthle cell neoplasm in 1 patient (2.8%). The interval between the first and second operation was a mean of 43.3 days (range, 2,103 d). Results At the primary surgery, 29 patients (80.6%) had a follicular variant of papillary carcinoma, 6 (16.7%) had follicular carcinoma, and 1 (2.8%) had Hürthle cell carcinoma. Of these, 14 had multifocal disease. In the completion lobe, 20 patients (55.6%) had evidence of thyroid carcinoma. There was a 0% incidence of RLN injury, and the mean pre- and post-completion thyroidectomy serum calcium was 8.9 mg/dL and 8.6 mg/dL, respectively. There was one postoperative hematoma, requiring re-exploration. Five patients (13.9%) had a transient postoperative serum calcium (Ca) <8.0 mg/dL, with one being symptomatic. None required vitamin D or prolonged calcium supplementation. Conclusions When completion thyroidectomy is necessary for the treatment of thyroid malignancy, the procedure can be performed safely with low morbidity and is effective for diagnosing and removing occult disease in the remaining thyroid. [source]

REVIEW ARTICLE: Reducing fracture risk with calcium and vitamin D

CLINICAL ENDOCRINOLOGY, Issue 3 2010
Paul Lips
Summary Studies of vitamin D and calcium for fracture prevention have produced inconsistent results, as a result of different vitamin D status and calcium intake at baseline, different doses and poor to adequate compliance. This study tries to define the types of patients, both at risk of osteoporosis and with established disease, who may benefit from calcium and vitamin D supplementation. The importance of adequate compliance in these individuals is also discussed. Calcium and vitamin D therapy has been recommended for older persons, either frail and institutionalized or independent, with key risk factors including decreased bone mineral density (BMD), osteoporotic fractures, increased bone remodelling as a result of secondary hyperparathyroidism and increased propensity to falls. In addition, treatment of osteoporosis with a bisphosphonate was less effective in patients with vitamin D deficiency. Calcium and vitamin D supplementation is a key component of prevention and treatment of osteoporosis unless calcium intake and vitamin D status are optimal. For primary disease prevention, supplementation should be targeted to those with dietary insufficiencies. Several serum 25-hydroxyvitamin D (25(OH)D) cut-offs have been proposed to define vitamin D insufficiency (as opposed to adequate vitamin D status), ranging from 30 to 100 nmol/l. Based on the relationship between serum 25(OH)D, BMD, bone turnover, lower extremity function and falls, we suggest that 50 nmol/l is the appropriate serum 25(OH)D threshold to define vitamin D insufficiency. Supplementation should therefore generally aim to increase 25(OH)D levels within the 50,75 nmol/l range. This level can be achieved with a dose of 800 IU/day vitamin D, the dose that was used in succesfull fracture prevention studies to date; a randomized clinical trial assessing whether higher vitamin D doses achieve a greater reduction of fracture incidence would be of considerable interest. As calcium balance is not only affected by vitamin D status but also by calcium intake, recommendations for adequate calcium intake should also be met. The findings of community-based clinical trials with vitamin D and calcium supplementation in which compliance was moderate or less have often been negative, whereas studies in institutionalized patients in whom medication administration was supervised ensuring adequate compliance demonstrated significant benefits. [source]