Simplified method for the determination of 25-hydroxy and 1alpha,25-dihydroxy metabolites of vitamins D2 and D3 in human plasma. Application to nutritional studies

A simplified method for the determination of 25-hydroxy and 1alpha,25-dihydroxy metabolites of vitamins D2 and D3 in human plasma was developed. Plasma samples were deproteinizated and applied to a Bond Elut C18OH cartridge to separate 25-hydroxyvitamin D (25-OH-D) and 1alpha,25-dihydroxyvitamin D [1,25(OH)2D] fractions. The 25-OH-D fraction was purified by a Bond Elut C18 cartridge and 25-OH-D2 and 25-OH-D3 were assayed by HPLC using a Zorbax SIL column. The 1,25(OH)2D fraction obtained above was subsequently applied to HPLC using a Zorbax SIL column to separate 1,25(OH)2D2 and 1,25(OH)2D3 fractions which were determined by a radioreceptor assay (RRA) using calf thymus receptor. The method was applied to nutritional studies.

Subclinical vitamin D deficiency in neonates: definition and response to vitamin D supplements

To determine the biological criteria for neonatal vitamin D deficiency, serum 25-hydroxyvitamin D (calcidiol), parathyroid hormone (PTH), calcium, phosphates, and alkaline phosphatase (ALP) activity were measured during the winter-spring period in 80 healthy neonates and their mothers 3-6 d after delivery. A longitudinal 3-mo survey of the serum biology of 52 of these neonates consuming formula was also performed to test the influence of their neonatal vitamin D status on the effects of two oral ergocalciferol supplements (500 and 1000 IU or 12.5 and 25 micrograms/d). At birth, 63.7% of the infants had calcidiol concentrations < or = 30 nmol/L. Most of them had no other biological sign evocative of vitamin D deficiency, but 14 neonates had low calcidiol concentrations and serum PTH concentrations > 60 ng/L, the upper limit of the adult normal range. They also had a significantly lower mean serum calcium concentration than did neonates with calcidiol concentrations > 30 nmol/L. On the basis of the association of low calcidiol concentrations (< or = 30 nmol/L) and high PTH concentrations (> 60 ng/L) as criteria for vitamin D deficiency, 24% of the neonates born to unsupplemented mothers were found to be vitamin D-deficient. Neonatal vitamin D status influenced the response of the infants to vitamin D supplements. Neonates with no sign of vitamin D deficiency showed similar changes in their serum calcidiol, calcium, phosphate, and PTH concentrations and ALP activity and no toxic effect (hypercalcemia or highly elevated calcidiol concentration) was observed whatever their vitamin D intake. In contrast, neonates with subclinical vitamin D deficiency had normalized serum PTH within 1 mo only when they were given 1000 IU ergocalciferol (25 micrograms)/d in addition to their formula.

Recovery from metabolic bone disease in a girl with vitamin D deficiency rickets associated with primary hyperparathyroidism

We describe a 13 year-old Ethiopian girl with vitamin D deficiency rickets. Hypercalcemia, increased serum alkaline phosphatase and PTH levels, together with low serum levels of 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D suggested the co-existence of primary hyperparathyroidism. The surgical removal of a parathyroid adenoma led to bone healing and normalization of blood chemistry. We conclude that vitamin D deficiency masked the hyperparathyroidism and hypercalcemia, while excess PTH secretion delayed the cure of rickets until successful parathyroidectomy had been carried out.

Vitamin D prophylaxis in children with a single dose of 150000 IU of vitamin D

OBJECTIVE

To determine the efficacy of a single oral dose of 150,000 IU of vitamin D2 at the beginning of autumn for preventing winter vitamin D deficiency in children in Ushuaia (55 degrees S).

DESIGN

The study was prospective.

SUBJECTS

79 children clinically healthy with 8.6 +/- 1.4 y of age (X +/- s.d.).

INTERVENTIONS

Fasting serum venous samples and 2 h urine samples were obtained immediately before and 6 w and 5 mon after the vitamin D dose. Parents informed consent was obtained previous to the study. In a subgroup of 30 children serum levels of calcium (sCa), phosphorus (sP), total alkaline phosphatase (TAP), 25 hydroxyvitamin D (25 OHD), parathyroid hormone (PTH) and the urine calcium/creatinine ratio in a 2 h urine sample (UCa/UCreat) were measured. In the whole group sCa and the ratio uCa/ucreat were measured.

RESULTS

After 150,000 IU of vitamin D2 administration, serum 25 OHD levels at the end of winter (17.0 +/- 9.4 ng/ml) were similar to those at the beginning of autumn (18.7 +/- 10.7 ng/ml), but significantly higher from those obtained in a previous study without vitamin D (9.8 +/- 3.8 ng/ml, P < 0.001). PTH levels were higher at the end of winter (P < 0.02), but this augmentation was lower than the increment observed without vitamin D. Plasma calcium levels and the urine calcium/creatinine ratio were lower at 5 months after vitamin D2 dose (P < 0.02 and P < 0.05 respectively). In the total group the serum calcium was lower after the fifth month (P < 0.05). The Uca/Ucreat ratio was lower at 6 w and 5 mon (P < 0.05 and P < 0.001).

CONCLUSION

A single dose of 150,000 IU of vitamin D maintained appropriate levels of 25 OHD without inducing hypercalcemia nor hypercalciuria, but a winter increment of PTH (smaller than in the group without vitamin D) was not inhibited.

Prospective randomized study of sulindac versus calcium and calciferol for upper gastrointestinal polyps in familial adenomatous polyposis

Eighteen patients with familial adenomatous polyposis (FAP) who had previously undergone colectomy but had upper gastrointestinal polyps were studied in a double-blind randomized crossover trial comparing sulindac with calcium and calciferol. Sulindac produced a reduction in the crypt proliferation index in the gastric epithelium of patients but did not significantly affect duodenal mucosa. Calcium with calciferol did not have any effects on crypt proliferation index in patients with FAP.

1 alpha-Hydroxy-vitamin D2: a new look at an 'old' compound

Calcitriol is effective in suppressing PTH levels in haemodialysis patients with hyperparathyroidism but has a low therapeutic index. There is a search for other vitamin D sterols that suppress PTH but cause less hypercalcaemia. We review evidence that 1 alpha-hydroxy-vitamin D2 (1 alpha-D2) may be an effective and safer alternative to calcitriol. In vitamin D-deficient rats, 1 alpha-D2 is equipotent to 1 alpha-D3, which is converted to calcitriol before it acts; but, in normal rats, 1 alpha-D2 is much less toxic at high doses. In osteopenia models, either steroid-induced or following ovariectomy, 1 alpha-D2 is equal to or more effective than 1 alpha-D3 in preventing bone loss but causes less hypercalciuria. Studies in osteoporotic women reveal minimal hypercalciuria with 1 alpha-D2 at doses up to 4 micrograms/day, data suggesting greater safety than reported with calcitriol or 1 alpha-D3. Preliminary data in haemodialysis patients with secondary hyperparathyroidism demonstrate the efficacy of 1 alpha-D2 in suppressing PTH levels with minimal untoward effects on serum Ca and no effects on serum P. Taken together, these observations suggest that 1 alpha-D2 deserves strong consideration as a therapeutic agent for secondary hyperparathyroidism associated with end-stage renal disease.

A comparison of the effects of alfacalcidol treatment and vitamin D2 supplementation on calcium absorption in elderly women with vertebral fractures

Although vitamin D supplementation in the frail elderly improves calcium absorption, suppresses parathyroid hormone, decreases bone loss and reduces the risk of fractures, such treatment may be ineffective in patients with vertebral osteoporosis, because of impaired vitamin D metabolism or resistance to the action of vitamin D metabolites on the bowel. We have therefore performed a randomized, single masked study comparing the effects of alfacalcidol treatment (0.25 micrograms twice daily) and vitamin D2 supplementation (500-1000 units daily) on calcium absorption and bone turnover in 46 elderly women (median age 69 years, range 64-79 years) with radiological evidence of vertebral fractures. Serum 25-hydroxyvitamin D increased significantly after 3 and 6 months of treatment with vitamin D2 (p < 0.001), but was unchanged in the group receiving alfacalcidol. Serum 1,25-dihydroxyvitamin D did not change significantly in either group over the study period. Fractional 45Ca absorption increased after 3 months of treatment with alfacalcidol (p < 0.05), but was unchanged with vitamin D2. There was also a reduction in plasma intact parathyroid hormone and serum alkaline phosphatase after 6 months of treatment with alfacalcidol (p < 0.05) which was not seen in the group receiving vitamin D2. Our study shows that vitamin D2 supplementation is ineffective in stimulating calcium absorption in elderly women with vertebral osteoporosis. By increasing calcium absorption in such patients, alfacalcidol may prove more effective than vitamin D in the management of vertebral osteoporosis.

Functional improvement with vitamin D replenishment in a cohort of frail, vitamin D-deficient older people

OBJECTIVE

To evaluate functional improvement in a population of frail, homebound older persons with low vitamin D status as vitamin D stores improve.

DESIGN

Randomized, controlled intervention study.

SETTING

Subjects' homes and a nursing facility in Baltimore, Maryland.

PARTICIPANTS

The first 32 subjects (community-dwelling, homebound older subjects from the Johns Hopkins Elder Housecall Program and nursing home residents from the Johns Hopkins Geriatrics Center) entered in a longitudinal study of vitamin D replacement.

MEASUREMENTS

Baseline 25-hydroxyvitamin D levels were measured and repeated at least 1 month after therapy with either placebo or vitamin D (ergocalciferol). Subjects were also administered the Frail Elderly Functional Assessment (FEFA) questionnaire, an instrument demonstrated to be reliable, valid, and sensitive to small increments of functional change in this population.

MAIN RESULTS

All subjects started with 25-hydroxyvitamin D levels less than 15 ng/mL. Those subjects whose levels improved by at least 3 ng/mL (> assay coefficient of variation) also demonstrated improvement in FEFA score. Regression analysis between change in FEFA score compared with change in 25-hydroxyvitamin D was significant (r = .4; P = .02).

CONCLUSIONS

In this cohort of homebound older people, improvement in vitamin D status was associated with functional improvement as measured by the FEFA questionnaire.

[Fahr syndrome and dysparathyroidism. 3 cases]

Fahr's disease associates various degrees of neuropsychological impairment and calcium deposits in the basal ganglia. We report 3 cases. The first case was a 54-year-old man with hemichorea of one-year duration. Laboratory results demonstrated idiopathic hypoparathyroidism. In the second case, a 23-year-old man treated for epilepsia for 8 years was hospitalized for subintrant episodes and hemichorea. Dysmorphism and laboratory results led to the diagnosis of pseudo-hypothyroidism. The third case was a 62-year-old woman with generalized seizures of epilepsia and dementia of two-month duration. Physical examination revealed extra-pyramidal rigidity. Hyperparathyroidism due to an adenoma was confirmed histologically. In all three patients, correction of phosphocalcium levels led to clinical improvement, particularly with disappearance of the epileptic seizures and abnormal movements. Clinical expression of Fahr's syndrome varies greatly. Symptoms include psychiatric disorders, epileptic seizures, extra-pyramidal syndrome and various neurological conditions. Diagnosis requires CT brain scan which identifies calcium deposits in the basal ganglia. The main cause is hypoparathyroidism, whether primary or post-operative. Cases due to other causes of dysparathyroidism are rare. The pathophysiology of this condition remains unknown and results of treatment are often unsatisfactory. Since correcting the impaired calcium phosphorus metabolism often leads to considerable improvement, it is essential to systematically search for dysparathyroidism in patients presenting with neuropsychologic manifestations associated with calcifications of the basal ganglia.

Cyclical etidronate plus ergocalciferol prevents glucocorticoid-induced bone loss in postmenopausal women

OBJECTIVE

To assess the benefit of cyclical etidronate plus ergocalciferol for the prevention of glucocorticoid-induced bone loss in a 2-year, prospective, open study based in an osteoporosis clinic.

PATIENTS AND METHODS

Group 1 consisted of 15 postmenopausal women (mean age 62.6 +/- 3.3 years) who commenced glucocorticoid therapy and were treated with cyclical etidronate (400 mg/d for the first month; thereafter, 400 mg/d for 2 weeks of every 3-month period), elemental calcium (1 g/d), and ergocalciferol (0.5 mg/wk). Group 2 consisted of 11 postmenopausal women (mean age 60.2 +/- 4.7 years) with glucocorticoid-induced osteoporosis, who were attending the clinic at the same time and were treated with calcium supplements only (1 g/d).

MEASUREMENTS

Lumbar spine and femoral neck bone mineral densities (BMD) were measured at baseline and after 12 and 24 months of glucocorticoid therapy using a dual energy x-ray absorptiometer.

RESULTS

The two groups did not differ with respect to age, years since the menopause, mean daily glucocorticoid dose, and baseline BMD values. During the first year of therapy, mean lumbar spine BMD increased from an initial value of 0.88 g/cm2 to 0.94 g/cm2, an increase of 7% per year (95% confidence interval [CI] 3.7% to 10.2%; P < 0.001 compared with controls). Significant increases in BMD of 2.5% per year were also observed in the femoral neck (95% CI -1% to 6%; P < 0.01 compared with controls). After the second year of cyclical etidronate therapy, femoral neck BMD continued to increase (P < 0.05 compared with value at 12 months), while lumbar spine BMD remained stable.

CONCLUSION

Chronic glucocorticoid therapy may result in bone loss at most skeletal sites. Therapy with cyclical etidronate plus ergocalciferol not only prevented glucocorticoid-induced bone loss, but even increased lumbar spine and femoral neck BMD in postmenopausal women commencing glucocorticoid therapy.

[Correction of disturbances in acid-base status and metabolism of metabolites of the oxidative-reductive reaction in rickets]

The disturbance of redox and acid-base state in the tissues of rats with experimental rickets and in clinics has been studied. It was shown that administration of namacit for the directed correction of the disturbance of homeostasis allows decreasing the doses of vitamin D.

[Hypophosphatemic osteomalacia acquired after renal transplantation: a a cause of severe osteoporosis]

Renal osteodystrophy improves after renal transplantation but, after the procedure, other forms of bone disease emerge. We report a male patient that received a renal allograft four years before, who consulted for low back pain secondary to multiple vertebral compression fractures. The patient had good renal function, a parathormone independent hyperphosphaturia, normal 25-OH cholecalciferol, increased urinary hydroxyproline, decreased osteocalcin, reduced bone density and a bone biopsy revealing osteomalacia. The diagnosis of hypophosphatemic osteomalacia was reached and treatment with phosphates and ergocalciferol was started but, despite this, the patient suffered a new fracture two years later. Two mechanisms can produce hypophosphatemia after a renal transplantation: a parathormone excess due to the previous renal failure, that disappears during the first year after the transplantation or a derangement in renal phosphate transport that can be due to a generalized proximal tubule solute transport derangement (Fanconi syndrome), parathormone hypersensitivity or to an "idiopathic" hyperphosphaturia. Despite a good treatment, bone mass is not recovered and there is a high fracture risk. Mineral metabolism must be closely monitored after a renal allograft and its alterations must be quickly treated.

Single-day therapy for nutritional vitamin D-deficiency rickets: a preferred method

A single-day large dose of vitamin D (stosstherapy) was given to 42 patients with nutritional vitamin D-deficiency rickets. Stosstherapy is safe and effective, obviates problems with compliance, and, by evoking a response in 4 to 7 days in nutritional rickets, becomes a valuable diagnostic aid for patients in whom initial findings do not clearly distinguish nutritional rickets from familial hypophosphatemic rickets.

Parathyroid autotransplantation in patients undergoing a total thyroidectomy: a review of 261 patients

Parathyroid autotransplantation was first described in 1907 by Halsted. However, this simple and effective method of preserving parathyroid function has been used with increasing frequency only during the past 25 years. Beginning in the late 1960s, our group has transplanted normal parathyroid tissue into the ipsilateral sternocleidomastoid muscle whenever these glands could not be preserved in situ with adequate blood supply. In addition, if the blood supply of all four parathyroid glands appeared compromised, cryopreservation of parathyroid tissue was performed in case the autotransplanted tissue did not function after surgery. Since 1970, 393 patients underwent a total thyroidectomy. Parathyroid glands that could not be saved in situ were biopsied to confirm their identity by frozen section and then autotransplanted. Of the 393 patients who underwent a total thyroidectomy, 261 patients required transplantation of one or more glands. Among those 261 patients who underwent selective parathyroid autotransplantation, 33 (13%) required temporary calcium and vitamin D supplementation. Of these 33 patients, 2 (less than 1%) had permanent hypoparathyroidism and are receiving long-term vitamin D therapy.

Marked decrease in trabecular bone quality after five years of sodium fluoride therapy--assessed by biomechanical testing of iliac crest bone biopsies in osteoporotic patients

Sodium fluoride has for more than 2 decades been a commonly used therapeutic agent for established osteoporosis because of a repeatedly documented anabolic effect on trabecular bone mass. Recently, however, three controlled trials have failed to demonstrate any therapeutic advantage of NaF over placebo with respect to vertebral fracture rate. Also, there have been several reports of an increased incidence of nonvertebral fractures during fluoride administration. Thus, the efficacy of fluoride therapy remains a controversial issue. The aim of this longitudinal study was to investigate the effect of sodium fluoride (40-60 mg per day), calcium (45 mmol), and vitamin D2 (18,000 IU) on trabecular bone strength, assessed before and after 1 or 5 years of treatment for osteoporosis. Iliac crest biopsies were taken before and after 1 year of treatment in 12 patients, and before and after 5 years of treatment in 14 patients. Measurements were made of biomechanical competence, ash content, and bone fluoride content, and bone strength parameters were normalized for ash content, thereby obtaining a measure of trabecular bone quality. Bone fluoride content was significantly increased after both 1 and 5 years of treatment, indicating that the administered fluoride had been ingested. After 1 year of treatment, no difference was observed in iliac crest trabecular bone ash content. A general trend for decreased bone strength and bone quality was observed, but this was insignificant. After 5 years of fluoride treatment, an insignificant decrease in iliac crest trabecular bone ash content was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of increasing doses of 1 alpha-hydroxyvitamin D2 on calcium homeostasis in postmenopausal osteopenic women

This study is the first reported administration of 1 alpha-hydroxyvitamin D2 (1 alpha-OHD2) to human subjects. A total of 15 postmenopausal osteopenic women were given increasing oral doses of 1 alpha-OHD2, beginning with a low dose of 0.5 microgram/day. In 15 subjects, the doses were raised at weekly intervals to 1.0, 2.0, 4.0, and 5.0 micrograms/day, and in 5 of these subjects, the dose was further increased to 8.0 or 10.0 micrograms/day. Mean urine calcium +/- SEM showed a dose-related increase from 134 +/- 17 mg/24 h on 0.5 microgram/day to 198 +/- 21 mg/24 h on 4.0 micrograms/day (p < 0.05) and to 241 +/- 35 mg/24 h on 5.0 micrograms/day (p < 0.05). No subjects had hypercalciuria (> 350 mg/24 h, the upper limit of the laboratory normal range) at doses less than 5.0 micrograms/day; 5 subjects had hypercalciuria at or above 5.0 micrograms/day (3 at 5.0 micrograms/day, 1 at 8.0 micrograms/day, and 1 at 10.0 micrograms/day). Mean serum calcium increased slightly on the 4.0 micrograms dose only (p < 0.05) but remained well within the normal range. Mean creatinine clearance and BUN, used as measures of renal function, showed no significant changes. Routine blood and urine assays also showed no significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe vitamin D deficiency in Auckland

AIMS

To study the presentation of severe vitamin D deficiency in Auckland and to determine if appropriate therapy was given.

METHODS

Retrospective review of records of patients with very low plasma 25 hydroxyvitamin D concentrations (< or = 12.5 nmol/L or 5 micrograms/L).

RESULTS

Fifty cases were identified over a two year period. 28 subjects had recognised risk factors for vitamin D deficiency (such as gastrointestinal disease or greatly reduced food intake). The majority of the other 22 subjects were elderly residents of rest homes or private hospitals. Low body weight and reduced mobility were common features of both groups. Increased plasma alkaline phosphatase activity and hypocalcaemia were the most frequent biochemical findings. Appropriate treatment with high dose calciferol had been given to only 28% of the subjects.

CONCLUSIONS

Severe vitamin D deficiency does occur in Auckland despite its low latitude. Low body weight, reduced mobility and lack of sun exposure are particular risk factors. Appropriate therapy is cheap, safe and effective but many patients with severe vitamin D deficiency are being managed suboptimally.

Tertiary hyperparathyroidism during high phosphate therapy of familial hypophosphatemic rickets

We report the development of severe tertiary hyperparathyroidism in three girls treated for familial hypophosphatemic rickets and characterize parathyroid function in vivo and in vitro. All patients had been previously treated with relatively large doses of inorganic phosphorus (125 mm/day) and ergocalciferol or calcitriol for several years and had radiographic evidence of long-standing hyperparathyroidism. Even in the presence of extremely elevated PTH levels, oral phosphate lowered serum calcium levels in vivo and further stimulated PTH secretion. Profound multiglandular parathyroid hyperplasia was found in each patient at surgery. Examination of the secretory characteristics of the excised parathyroid tissue revealed that either relatively high calcium concentrations were generally needed to suppress PTH secretion or PTH secretion was not suppressible. Caution is recommended when relatively large doses of phosphate are used to treat familial hypophosphatemic rickets.

Annual injection of vitamin D and fractures of aged bones

In order to investigate the effect of a supplementation of vitamin D in the prophylaxis of fractures of the bones of aged people, an annual intramuscular injection of ergocalciferol (150,000-300,000 IU) was given to two series of aged subjects: first to 199 (45 male) of 479 subjects (110 male) aged more than 85 years who were living in their own home, and second to 142 (29 male) of 320 (58 male) subjects aged 75-84 and living in a home for aged people. This prospective series was divided into treatment groups according to month of birth. These injections were given annually from September to December in the years 1985-1989, two to five times to each participant. The fracture rates, laboratory values, vitamin D levels, possible side effects, and mortality were followed until October 1990. A total of 56 fractures occurred in the 341 vitamin D recipients (16.4%) and 100 in 458 controls (21.8%) (P = 0.034). The fracture rate was about the same in both outpatient and municipal home series. Fractures of the upper limb were fewer in the vitamin D recipients, 10/341 = 2.9% (P = 0.025), than in the controls, 28/458 = 6.1%, during the follow-up. A similar result was obtained in fractures of ribs, 3/341 = 0.9% and 12/458 = 2.6%, respectively. Fractures of the lower limbs occurred almost as frequently, 31/341 = 9.1%, among the vitamin D recipients as among the controls, 49/458 = 10.7%. The fracture rate was higher in females (22.2%) than in males (9.5%). The fractures were fewer in the vitamin D recipients only in females.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcinosis and metastatic calcification due to vitamin D intoxication. A case report and review

Vitamin D, a fat-soluble vitamin, can be associated with significant morbidity when prescribed in large doses. We describe a hypoparathyroid patient with vitamin D intoxication who developed painful periarticular calcinosis, nephrocalcinosis with hypertension and chronic renal failure in addition to band keratopathy and hearing loss. He was treated with combination therapy including prednisone, phosphate-binding antacid, phenytoin and disodium etidronate. After 20 months of follow-up there was a significant reduction of periarticular calcinosis, but no improvement in renal function, band keratopathy or hearing loss and possible calcification of the ossicles. The clinicopathologic features of metastatic calcification and the various treatment modalities are reviewed.