Oral Calcium Supplementation Research Articles

Treatment of osteoporosis with calcitonin, with and without growth hormone

A 24 month randomized parallel study of the treatment of postmenopausal osteoporosis with calcitonin alone v calcitonin alternating with growth hormone (combined treatment) was conducted. Each group received 1000 mg daily of oral calcium supplements. The rate of change in total body calcium for the combined and calcitonin groups was +1.68%/yr and +1.33/yr, respectively ( P < .05). However, the difference in the two groups was not statistically significant. Further, the total body calcium level did not increase after 12 to 18 months of treatment. There was a significant difference in the rates of change of bone mineral content (BMC) of the radius for the two groups, with a loss of BMC in the combined treatment group ( F = 4.80, P < .05). Calcitonin treatment is effective in producing an increment in bone mass. The addition of growth hormone to this regimen appears to have a deleterious effect on cortical bone mass.

Calcium Metabolism and the Renin-Aldosterone System in Essential Hypertension

Despite recent appreciation of a role for calcium in clinical hypertension, evidence at present is conflicting. Thus, certain studies suggest increased calcium availability may be associated with increased levels of blood pressure, while others suggest that a calcium deficiency may contribute to the pathogenesis of hypertensive disease. Our own group has thus far demonstrated deviations of circulating levels of ionized calcium and of magnesium in essential hypertension, linked with concurrent deviations in the activity of the renal pressor hormone, renin. Furthermore, calcium metabolic indices may predict and even determine dietary sodium sensitivity in hypertension, as well as the blood pressure responsiveness to antihypertensive drug therapy. Moreover, oral calcium supplementation may itself possess antihypertensive actions in specifically targeted renin subgroups of essential hypertensive subjects. Altogether, these results link calcium metabolism, renin system activity, and the pathogenesis of hypertensive disease. It may ultimately be calcium-regulating hormones, which determine cellular disposition of calcium, rather than circulating levels of calcium itself, that mediate the blood pressure and possibly even the renin deviations observed among differing hypertensive individuals.

Relation between gastric secretion of acid and urinary excretion of calcium after oral supplements of calcium.

The object of this study was to determine in 12 healthy subjects the relation between gastric secretion of acid and absorption of calcium from two different preparations of calcium, as judged from increased outputs of calcium in the urine. The increase in urinary output of calcium after solid calcium carbonate was greater in the subjects with the most gastric secretion of acid. The absorption of calcium after a solution of monocalcium citrate was independent of gastric secretion of acid. In the four subjects with the least gastric secretion of acid, there was no absorption of calcium after calcium carbonate, but the absorption after monocalcium citrate was as great as that for those who secreted greater amounts of acid.

Effect of early oral calcium supplementation on serum calcium and immunoreactive calcitonin concentration in preterm infants.

Oral calcium supplements (80 mg/kg per 24 h) were given to 23 preterm infants, and the course of serum calcium, magnesium, immunoreactive calcitonin, and gastrin was compared with a control group of 23 matched infants. In the supplemented group, serum calcium concentrations remained at the baseline level (2.31 mmol/l +/- 0.18 SD) while a fall (from 2.27 +/- 0.18 to 1.91 +/- 0.24 mmol/l) was observed at 12-16 hours of age in the control group, with 4 values < 1.75 mmol/l. There was no change in serum magnesium concentration in either group. The postnatal rise of serum immunoreactive calcitonin concentrations in the control group (from 171 +/- 135 to 493 +/- 273 pg/ml at 12-48 hours of age) was not found in the supplemented group. There was a negative correlation between serum calcium and immunoreactive calcitonin levels in the control group, but not in the supplemented group. There was no correlation between serum immunoreactive calcitonin and gastrin concentrations. These data show that oral calcium supplementation can prevent early neonatal hypocalcaemia, and suggest that this effect is achieved at least in part through a reduction of the postnatal rise of serum immunoreactive calcitonin.

Limit by hypherphosphatemia ofthe usefulness of vitamin D metabolites (1 α-hydroxycholecalciferol and 25-hydroxycholecalciferol) in the treatment of renal osteodystrophy

Nineteen patients who had been on maintenance hemodialysis for 33 months ,(± 13) with conditions optimized to prevent renal osteodystrophy (3 times week, a dialysate calcium of 7.0 mg/dl, oral calcium supplement and aluminum hydroxide to correct hypocalcemia and hyperphosphatemia, but with no vitamin D supplement) were treated with 1-alpha-HCC and 25-HCC (daily dosage of 1 and 50 μg respectively) for one year. This treatment was stopped every time the predialytic plasma levels of calcium and/or phosphate rose above 11.0 and 7.0 mg/di respectively in spite of an Increase in the prescribed dosage of aluminum hydroxide, and was resumed after normalization of plasma calcium and/or phosphate at reduced doses. The effect of vitamin D therapy was mainly assessed by histomorphometric evaluation of bone biopsies performed before initiating the treatment and 6 to 12 months later. Initially, no patient had histological evidence of osteomalacia as assessed by osteoid thickness Index, in spite of low plasma 25-HCC levels in 10 15 patients. 14 19 had hyperparathyroidism with extended active resorption surfaces (ARS) which were positively correlated with plasma PTH levels. During treatment, no patient developed osteomatacia. ARS Improved in 6 patients, worsened in 7 and remained unchanged In the 6 others, including 3 with initially normal values. When comparing worsened versus Improved patients, the aggravation of osteltis fibrosa was associated with increasing levels of plasma phosphate and pPTH. It is concluded that addition of vitamin D derivatives to optimal dialysis condlitions seems of questionable value because : 1) optimal dialysis conditions alone adequately prevent osteomalacla and most radiological osteitis fibrosa ; 2) vitamin D metabolite therapy may make plasma phosphate control more difficult which contributes to worsening of residual hyperparathyrodism.

Therapy of osteogenesis imperfecta with synthetic salmon calcitonin

We evaluated the long-term use of synthetic salmon calcitonin in the management of osteogenesis imperfecta tarda and congenita. Forty-eight children, ranging in age from 6 months to 15 years, and two young adults, received synthetic salmon calcitonin 2 MRC units/kg three days a week and a daily oral calcium supplement of 230 to 345 mg. The annual fracture rate was decreased during calcitonin therapy as compared to the period preceding therapy. There was an increase in the ability of the patient to stand and move and in the subjective feeling of strength in the lower extremities during calcitonin therapy. There was also a significant improvement in radiographic bone density, as determined by the method of photodensitometry, in patients under 5 years of age. Long-term administration of synthetic salmon calcitonin may be beneficial to young children with osteogenesis imperfecta.

Oral calcium supplementation in premature and asphyxiated neonates: Preliminary report

Biochemical and hormonal effects of oral calcium supplementation in premature and asphyxiated neonates during the first few days of life are described. Eight pairs of infants were matched for gestational age and one-minute Apgar score. One member of each pair served as a control and the other was given supplemental oral calcium (75 mg/kg/24 hr) beginning at 12 and ending at 72 hours of age. The supplemental infants had significantly higher serum calcium values both during the time of supplementation and for 36 hours after supplementation was stopped. The oral calcium supplements had no significant effect on serum concentrations of phosphate, magnesium, 25-hydroxy-vitamin D3, or parathyroid hormone, The incidence of hypocalcemia after 12 hours of age was 0 in eight supplemented infants and three in eight control infants. In patients at risk for hypocalcemia, prospective use of oral calcium supplements during the period when there is inadequate calcium intake from feedings may prevent hypocalcemia, appears to be without deleterious effect on measurable chemical and hormonal factors important in calcium homeostasis, and results in maintenance of higher serum calcium levels after supplementation has been discontinued.

The investigation and treatment of renal bone disease

Neutron activation analysis of a hand has been used to monitor changes in skeletal calcium content of patients undergoing maintenance hemodialysis. Assessed by this technic supplementary magnesium therapy was of value in reducing the progressive losses of skeletal calcium in a proportion of the patients receiving maintenance hemodialysis. Oral calcium supplements produced a decrease in the skeletal calcium losses of all the patients studied. 1-alpha-hydroxycholecalciferol, a potent vitamin D analogue, caused a significant increase in the calcium content of bone in three patients receiving maintenance hemodialysis; it may prove to be a safe and effective form of therapy for azotemic osteodystrophy.

Nephrology: An Annotated Bibliography of Recent Literature

Nephrology: An Annotated Bibliography of Recent Literature

Fat absorption in infants of birth weight less than 1,300 gm

Fat absorption was studied during the first 2 mo of life in 15 infants whose birth weights were less than 1,300 gm. Their capacity to absorb fat at 2 wk of age was midly impaired (79% of intake); it was significantly improved at 2 mo (88.4% of intake) and approached that of the adult. The degree of steatorrhea correlated inversely with intraluminal concentration of bile salts. In five infants who were given oral calcium supplements starting at 3 wk of age, fat excretion at 6–8 wk was significantly greater than in nonsupplemented infants.

Skeletal changes in patients treated by regular haemodialysis in the Sheffield area.

Abstract The incidence, type and degree of skeletal changes in 30 patients undergoing haemodialysis for chronic renal failure for over 18 months, are assessed by a radiological, clinical and biochemical study. This survey was also supported by bone biopsies in some of the cases. The main bone lesion was fracture. The fracture rate appeared to rise with the duration of haemodialysis. Osteosclerosis was noted in only one case and possibly was present in the pre-dialysis period while the appreciable decrease in bone density was seen in six patients. Fractures occurred more commonly in heavy patients with relatively high serum creatinine concentrations. Fractures were also commoner in patients who dialysed for long periods without a water softener and without taking oral calcium supplements.

Familial Hypoparathyroidism with Pregnancy- Challenging Issue for Patient as well as for Physician

Familial hypoparathyroidism is a rare cause of hypoparathyroidism. It may be x-linked recessive, autosomal dominant or autosomal recessive. In autosomal dominant hypoparathyroidism there is activating mutation of the calcium sensing receptor leading to inhibition of Parathormone (PTH) secretion at inappropriately low serum ionized calcium level. The disease often manifests in the first decade but may appear later. Clinical signs primarily involving neuromuscular disturbances including generalized seizure. Management of pregnancy in hypoparathyroidism is challenging as both under treatment and over treatment is dangerous for fetus. Treatment of hypoparathyroidism in pregnancy includes combination of oral calcium supplementation with calcitriol with an aim to keep serum calcium within normal range. Here we discussed a case of 21 year pregnant lady with familial hypoparathyroidism with successful delivery of a healthy baby. Key words: Hypoparathyroidism; Hypocalcaemia; Hyperphosphataemia; Epilepsy. DOI: http://dx.doi.org/10.3329/fmcj.v6i2.9215 FMCJ 2011; 6(2): 113-115

Adult-onset vitamin-D-resistant hypophosphatemic osteomalacia. Effect of total parathyroidectomy.

A 27-year-old man with disabling adult-onset hypophosphatemic osteomalacia was studied in 1947. Because of the failure of large doses of vitamin D, with oral calcium and phosphate supplements, to induce calcium retention on prolonged metabolic balance studies, total parathyroidectomy was performed. Bone healing ensued and subsequently tetany has been easily controlled with modest doses of vitamin D. On restudy in 1968 (after vitamin D had been discontinued) both serum phosphate and renal phosphate clearance were in the range expected in hypoparathyroidism. Intravenous administration of parathyroid hormone reproduced the high phosphate clearance that had been present before parathyroidectomy. The data indicate a causal or permissive role of parathyroid hormone in the renal phosphate leak, hypophosphatemia and osteomalacia in this patient.

Chronic cholangitides: aetiology, diagnosis, and treatment.

A number of different chronic diseases affect the intrahepatic bile radicles or cholangioles. They include primary and secondary sclerosing cholangitis, primary biliary cirrhosis, chronic cholestatic drug jaundice, atresia, and carcinoma. Aetiological factors include infection, immunological changes, hormones, and congenital defects.Patients with chronic cholestasis have decreased bile salts in the intestinal contents and suffer from a bile salt deficiency syndrome. Failure to absorb dietary fat is managed by a low-fat diet and by medium-chain trigly-cerides which are absorbed in the absence of intestinal bile salts. Fat-soluble vitamin deficiencies are prevented by parenteral vitamins A, D, and K(1). Calcium absorption is defective, and improvement may follow intramuscular vitamin D, medium-chain triglycerides, a low-fat diet, and oral calcium supplements.In partial intestinal bile salt deficiency the anionic bile-salt-chelating resin cholestyramine controls pruritus though steatorrhoea increases. Pruritus associated with total lack of intestinal bile salts is managed by methyl-testosterone or norethandrolone, though the jaundice increases.

A CRITICAL EVALUATION OF THE TRISODIUM-EDETATE TEST FOR HYPOPARATHYROIDISM AFTER THYROIDECTOMY

The trisodium edetate (T.S.E.) infusion test for parathyroid hypofunction has been used in 60 patients selected from a large group of postthyroidectomy patients on a basis of clinical or anatomical suspicion of hypoparathyroidism. 39 were considered to have shown a subnormal response to the T.S.E. infusion test and 24 of these, who also had symptoms possibly suggestive of hypoparathyroidism, took part in a double-blind trial of treatment with calcium gluconate (equivalent to 720 mg. of calcium per day) versus a placebo. The oral calcium supplement was shown to have no significant effect on symptoms or on serum-calcium. The T.S.E. infusion test failed to indicate a need for treatment for hypoparathyroidism. Moreover the test has proved to be non-specific as an index of parathyroid function since in 1 patient a subnormal T.S.E. response reverted to normal when the patient was given maintenance treatment with calciferol. The longer the interval between thyroidectomy and the T.S.E. test the less likely were patients to show any hypocalcæmic symptoms during or after the test.

Parkinsonism in Postoperative Hypoparathyroidism

CALCIFICATION in the region of the basal ganglia occurs in a number of disease states and may be associated with the clinical features of parkinsonism. Such calcification is seen frequently in idiopathic- and pseudohypoparathyroidism.1In contrast, it is reported to be of rare occurrence in postoperative hypoparathyroidism.2,3 The purpose of this report is to present three patients who developed parkinsonism following thyroidectomy, two of whom had calcification in the region of the basal ganglia. The relation between hypoparathyroidism, basal ganglia calcification, and parkinsonism will be discussed. Report of Cases Case 1. —A 68-year-old woman (HFH 05-10-18) had a subtotal thyroidectomy for a nontoxic goiter in 1940. Following this operation, she experienced hoarseness and muscle cramping which subsided after treatment with oral calcium supplements. The patient was then well until 1960, at age 65, when she experienced increasing fatigue, muscle stiffness, and leg cramps. She also noticed tremor of

PATHOGENESIS OF VITAMIN D-RESISTANT RICKETS AND THE RESPONSE TO A HIGH CALCIUM INTAKE.

Four patients with vitamin D-resistant rickets underwent simultaneous calcium47 kinetic and calcium, phosphorus and nitrogen balance studies before and after the institution of a high calcium intake. The renal tubular transport of phosphorus was evaluated by the response to a 9-hr calcium infusion. Bone formation and resorption were 2–5 times normal in all patients. Oral calcium supplements produced a 20–30% reduction in bone resorption, but little initial change in bone formation. Long-term supplements in all patients produced a gradual and parallel fall of the skeletal turnover and serum alkaline phosphatase. The intestinal absorption of calcium was subnormal in the presence of probable secondary hyperparathyroidism. No defect in the renal tubular transport of phosphorus could be demonstrated with calcium infusion.