Prevention of bone loss in cardiac transplant recipients. A comparison of biphosphonates and vitamin D. Randomised controlled trial of calcium and supplementation with cholecalciferol (vitamin D3) for prevention of fractures in primary care. Double-blind randomized, crossover trial of calcium supplementation in essential hypertension. Effects of a short-term vitamin D and calcium supplementation on body sway and secondary hyperparathyroidism in elderly women. Controlled trial of long-term oral calcium supplementation in essential hypertension. Calcium treatment of essential hypertension in elderly patients evaluated by 24 H monitoring. Calcium supplementation in patients with essential hypertension: assessment by office, home and ambulatory blood pressure. Skeletal site selectivity in the effects of calcium supplementation on areal bone mineral density gain: a randomized, double-blind, placebo-controlled trial in prepubertal boys. World Health Organization randomized trial of calcium supplementation among low calcium intake pregnant women.
Bone mineral density is already abnormally reduced at the moment of cardiac transplantation and bone loss occurs at an impressive rate in the first postoperative year. The aim of the study was to compare two prophylactic medical regimens as to their efficacy in mitigating bone loss after transplantation. Forty-eight consecutive recipients were randomized to receive either alternating calcium carbonate and disodium etidronate (group A) or a daily supplement of calcium carbonate and alphacalcidol (group B). Bone mineral density measurements were performed immediately before hospital discharge and 6, 12, and 24 months after surgery using dual energy X-ray absorptiometry. Clinical events were recorded and roentgenograms of the spine were performed postoperatively and 1 and 2 years later. In both treatment groups bone loss remained significant at the level of the lumbar spine in the first postoperative year (P<0.005) and at the level of the femoral neck in the first (P<0.005) and the second (P<0.06) year after transplantation. Six months after transplantation, however, patients receiving alphacalcidol had a significant reduction in bone loss at the level of the lumbar spine (P=0.047) and at the level of the femoral neck (P=0.043). At the level of the femoral neck this decrease in bone loss was even more pronounced in the second postoperative year (P<0.001). In the group of patients treated with disodium etidronate, 4 recipients needed additional hospitalizations for treatment of symptomatic fractures at the level of the lumbar spine or the femoral neck. No such events happened in recipients receiving vitamin D supplements. Prophylactic administration of calcium carbonate and alphacalcidol after cardiac transplantation reduces bone loss and seems to decrease osteoporotic complications. To assess whether supplementation with calcium and cholecaliferol (vitamin D3) reduces the risk of fracture in women with one or more risk factors for fracture of the hip.
                Pragmatic open randomised controlled trial.
                Practice nurse led clinics in primary care.
                3314 women aged 70 and over with one or more risk factors for hip fracture: any previous fracture, low body weight (< 58 kg), smoker, family history of hip fracture, or fair or poor self reported health.
                Daily oral supplementation using 1000 mg calcium with 800 IU cholecaliferol and information leaflet on dietary calcium intake and prevention of falls, or leaflet only (control group).
                Primary outcome measure was all clinical fractures and secondary outcome measures were adherence to treatment, falls, and quality of life (measured with the SF-12).
                69% of the women who completed the follow-up questionnaire at 24 months were still taking supplements (55% with inclusion of randomised participants known to be alive). After a median follow-up of 25 months (range 18 to 42 months), clinical fracture rates were lower than expected in both groups but did not significantly differ for all clinical fractures (odds ratio for fracture in supplemented group 1.01, 95% confidence interval 0.71 to 1.43). The odds ratio for hip fracture was 0.75 (0.31 to 1.78). The odds of a woman having a fall at six and 12 months was 0.99 and 0.98, respectively. Quality of life did not significantly differ between the groups.
                We found no evidence that calcium and vitamin D supplementation reduces the risk of clinical fractures in women with one or more risk factors for hip fracture. Registration ISRCTN26118436, controlled trials registry. In a double-blind, randomized, placebo-controlled, crossover trial, 23 middle-aged patients with mild to moderate essential hypertension were given an oral calcium supplement (1 g/day) for 8 weeks. At the end of this period, eight patients continued with this treatment for an additional 2 weeks but were also given 0.5 micrograms/day of 1,25-(OH)2 vitamin D3. In the 21 patients who completed the study, arterial pressure during the calcium-supplemented phase was almost identical to that of the placebo phase. In eight patients, mean arterial pressure (MAP) had changed by greater than 5 mmHg at the end of the calcium-supplemented period, compared with the end of the placebo phase (six patients showed an increase in MAP and two a decrease). Changes in arterial pressure were unrelated to age, plasma ionized calcium, parathyroid hormone (PTH), plasma renin activity (PRA), plasma aldosterone, 24-h urinary calcium, sodium and potassium and were only weakly related to body weight. In the eight patients who continued with the treatment of calcium plus 1,25-(OH)2 vitamin D3 after the 8-week study period, arterial pressure changed very little and not significantly. These results do not support the suggestion that calcium supplements lower arterial pressure in middle-aged subjects with mild to moderate essential hypertension. 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. A randomized, double-blind, placebo-controlled crossover trial of oral calcium supplementation was carried out in 18 patients with uncomplicated essential hypertension. After 15 weeks of oral calcium supplementation, 1 g/day, of the patients' habitual diet, the only blood pressure change (compared with the results of placebo treatment) was in the average standing systolic blood pressure, which was significantly reduced (-8.6 mm Hg; p less than 0.01). The 24-hour urinary calcium excretion and the total serum calcium concentration increased significantly during calcium supplementation (p less than 0.05), indicating good compliance with the treatment. The individual blood pressure changes with high calcium intake were found to be inversely related to basal 24-hour urinary calcium excretion (r = -0.69, p less than 0.001 for standing systolic pressure; r = -0.55, p less than 0.002 for standing diastolic pressure). This correlation was independent of age, basal blood pressure, serum calcium concentration, basal 24-hour urinary sodium excretion, and body weight changes during the trial. In particular, a subgroup of six patients, who had a basal 24-hour urinary calcium excretion higher than the mean + 2 SD of a reference healthy population previously described, showed a substantial average blood pressure fall at variance with the other patients in the study. These results do not support the usefulness of an oral calcium supplement in the majority of subjects with mild essential hypertension; however, they suggest that a group of patients with a previously reported abnormality of calcium metabolism may be responsive to this therapeutic measure. We used 24-h monitoring of blood pressure (BP) to evaluate the effect of calcium supplementation on mild to moderate essential hypertension in elderly hospitalized patients for the first time in a controlled crossover study. The mean systolic and diastolic BP over a period of 24 h declined by 13.6 mm Hg (P less than .005) and 5.0 mm Hg (P less than .05) respectively in patients whose diet was supplemented with 1 g of elemental calcium in the form of oystershell electrolysate (AA calcium). Serum ionized calcium and urinary calcium and sodium excretion increased (serum Ca2+ 0.16 +/- 0.03 mEq/L, P less than .05; FECa 0.5 +/- 0.2%, P less than .05; FENa 0.4 +/- 0.1%, P less than .05) and plasma parathyroid hormone was suppressed (12.2 +/- 2.3 pg/mL, P less than .005). These data suggest that supplementation of dietary calcium may contribute to a reduction of BP in elderly patients with essential hypertension. To study the effects of a high calcium intake in hypertensive patients by blood pressure monitoring.
                In a randomized crossover study, patients were assigned to an 8-week calcium supplementation period and an 8-week control period. The subjects were given 25 mmol/day (1 g/day) of calcium as calcium carbonate during the intervention period.
                A hypertension clinic in a tertiary teaching hospital.
                Sixty untreated or treated hypertensive patients (35 men and 25 women, mean age 58 years) with office systolic/diastolic blood pressure > or = 140/90 mmHg.
                Office blood pressure, home blood pressure (last 7 days), and ambulatory 24 h blood pressure (every 30 min using TM-2421).
                The serum calcium concentration and urinary calcium excretion increased significantly with calcium supplementation. Office, home and 24 h blood pressure were lower in the calcium period than in the control period, although the differences were small (mean +/- SEM office blood pressure: 1.2+/-1.2/1.1+/-0.7 mmHg; home blood pressure: 1.9+/-0.7/1.3+/-0.6 mmHg; 24 h blood pressure: 1.2+/-0.8/0.9+/-0.5 mmHg,), and significant only for home systolic and diastolic blood pressures. The difference in home systolic blood pressure was inversely correlated with the level of home blood pressure in the control period and with the difference in urinary calcium. The difference in 24 h systolic blood pressure was positively correlated with the control level of urinary calcium. Age, sex, antihypertensive medication, drinking habit, sodium intake or order of treatment did not significantly influence the effects of calcium supplementation.
                An increase in calcium intake tends to lower office, home and ambulatory blood pressure in hypertensive patients. However, the antihypertensive effect is too small to support the general application of a high calcium intake in the treatment of hypertension. Calcium supplementation during childhood and adolescence is considered an early means of preventing osteoporosis in adults. Prepuberty is an opportune time for detecting the benefits of calcium in girls.
                The objective was to assess whether calcium supplementation increases bone mass gain in prepubertal boys in a skeletal site-specific manner.
                In a 12-month double-blind, placebo-controlled trial with 1-yr follow-up, 235 healthy prepubertal boys aged 7.4 +/- 0.4 yr (mean +/- sd) were randomized to receive two food products providing 850 mg/d calcium (calcium supplement group, n = 116) or an isocaloric placebo (n = 119). Areal bone mineral density (aBMD) was determined by dual-energy x-ray absorptiometry at radius (two sites), hip (two sites), femoral diaphysis (FDia), and L2-L4 vertebrae.
                At 12 months, aBMD gain was greater at the FDia and at the mean of the five appendicular skeletal sites in the calcium supplement group in both intention-to-treat analysis [76 +/- 32 vs. 64 +/- 33 mg/cm(2).yr; difference, 12.0 (95% confidence interval, CI, 3.6-20.3), P = 0.006; and 33 +/- 16 vs. 28 +/- 16 mg/cm(2).yr; difference, 5.1 (95% CI, 0.9-9.2); P = 0.018, respectively] and active treatment analysis [81 +/- 32 vs. 64 +/- 31 mg/cm(2).yr; difference, 17.2 (95% CI, 7.9-26.5); n = 174, P < 0.001; and 35 +/- 16 vs. 28 +/- 14 mg/cm(2).yr; difference, 7.5 (95% CI, 2.9-12.2); P = 0.002]. There was no beneficial effect of calcium on lumbar spine. The calcium effect was still detectable by ANOVA repeated measures analysis at the FDia (P = 0.004) and at the mean of the five appendicular skeletal sites (P = 0.002) 1 yr after the end of intervention (active treatment analysis). There was no change in bone size.
                In prepubertal boys, calcium-enriched foods increased aBMD at several appendicular skeleton sites, but not at the lumbar spine, and this without any bone size change. This effect was maintained 1 yr after treatment discontinuation. The purpose of this trial was to determine whether calcium supplementation of pregnant women with low calcium intake reduces preeclampsia and preterm delivery.
                Randomized placebo-controlled, double-blinded trial in nulliparous normotensive women from populations with dietary calcium < 600 mg/d. Women who were recruited before gestational week 20 received supplements (1.5 g calcium/d or placebo) throughout pregnancy. Primary outcomes were preeclampsia and preterm delivery; secondary outcomes focused on severe morbidity and maternal and neonatal mortality rates.
                The groups comprised 8325 women who were assigned randomly. Both groups had similar gestational ages, demographic characteristics, and blood pressure levels at entry. Compliance were both 85% and follow-up losses (calcium, 3.4%; placebo, 3.7%). Calcium supplementation was associated with a non-statistically significant small reduction in preeclampsia (4.1% vs 4.5%) that was evident by 35 weeks of gestation (1.2% vs 2.8%; P = .04). Eclampsia (risk ratio, 0.68: 95% CI, 0.48-0.97) and severe gestational hypertension (risk ratio, 0.71; 95% CI, 0.61-0.82) were significantly lower in the calcium group. Overall, there was a reduction in the severe preeclamptic complications index (risk ratio, 0.76; 95% CI, 0.66-0.89; life-table analysis, log rank test; P = .04). The severe maternal morbidity and mortality index was also reduced in the supplementation group (risk ratio, 0.80; 95% CI, 0.70-0.91). Preterm delivery (the neonatal primary outcome) and early preterm delivery tended to be reduced among women who were < or = 20 years of age (risk ratio, 0.82; 95% CI, 0.67-1.01; risk ratio, 0.64; 95% CI, 0.42-0.98, respectively). The neonatal mortality rate was lower (risk ratio, 0.70; 95% CI, 0.56-0.88) in the calcium group.
                A 1.5-g calcium/day supplement did not prevent preeclampsia but did reduce its severity, maternal morbidity, and neonatal mortality, albeit these were secondary outcomes.
There is no clear evidence that parenteral calcium supplementation impacts the outcome of critically ill patients.