High circulating levels of 25-hydroxyvitamin D₃in renal stone formers with hyperabsorptive hypercalciuria

Abstract

Normocalcaemic male stone formers, 31-51 years old (n = 108) on a free diet, were divided into a hypercalciuric group (n = 47) with calcium excretion rates higher than 8.0 mmol/24 h, a normocalciuric group (n = 32) with calcium excretion rates below 6.1 mmol/24 h and an intermediate group (n = 29). There were no statistically significant differences between the hypercalciuric and the normocalciuric groups with respect to serum levels of calcium, phosphate, creatinine, urate, ALAT, albumin, PTH, 1,25-dihydroxyvitamin D or urinary excretion of cAMP. The group of patients with high calcium excretion had significantly higher serum levels of 25-hydroxyvitamin D3 (75 +/- 4 nmol/l) than the group with low calcium excretion (57 +/- 4 nmol/l) (p less than 0.002), while the group of patients with intermediate calcium excretion had 25-hydroxyvitamin D3 levels between the other two groups (69 +/- 4 nmol/l). A highly accurate method based on isotope dilution-mass spectrometry was used to assay 25-hydroxyvitamin D3. Of the patients with hypercalciuria (n = 47), seven were classified as hyperabsorbers on the basis of calcium load tests. These patients were found to have even higher serum levels of 25-hydroxyvitamin D3 (108 +/- 10 nmol/l)--significantly higher than that of the hypercalciuric patients as a whole. The above study was carried out in March 1983. In September, the group of patients with high urinary calcium excretion also had significantly higher levels of 25-hydroxyvitamin D3 than the group of patients with low calcium excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary calcium is a determinant of bone mineral density in elderly men participating in the InCHIANTI study

“…The increase of serum concentrations of 25(OH)D in InCHIANTI participants with high calcium excretion is likely to be explained by larger vitamin D store [31], and may be associated with increased renal 1.25(OH) 2 D synthesis [16,32]. This association may be observed in hypercalciuric stone formers, and has been attributed to an abnormal renal 25(OH)D hydroxylation activity [16,33].…”

Persistent hypercalciuria and elevated 25-hydroxyvitamin D 3 in children with infantile hypercalcaemia

“…Large normal ranges of 25hydroxyvitamin D3 concentrations, their dependence on anti-rickets prophylaxis, seasonal variations and variable amounts of vitamin D3 in food products usually make impossible any interpretation of the results of random measurements of 25(OH)vitamin D3. High circulating levels of 25(OH)vitamin D3 in renal stone formers with hyperabsorptive hypercalciuria were reported [10]. Much more information is available on increased 1,25(OH)2vitamin D3 levels in variants of idiopathic hypercalciuria [9,11].…”

Association between Circulating Vitamin D Level and Urolithiasis: A Systematic Review and Meta-Analysis

“…After full-text analysis, another 19 studies were excluded for the following reasons: 14 had no control group and no useful data, three did not provide standard deviations, and two reported duplicate data. Finally, 32 studies fulfilled our eligibility criteria and were enrolled in the meta-analysis [10,11,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47]. …”

“…Most studies clearly demonstrated that they ruled out hyperparathyroidism and/or renal tubule acidosis [10,11,18,19,22,26,27,29,33,34,36,43], some also excluded patients using calcium and/or vitamin D [18,26,29,35,39,42]. Seventeen studies described their criteria of hypercalciuria and they were not consistent [18,19,20,22,24,26,28,29,32,35,36,37,38,42,43,45], twelve of which defined hypercalciuria as urinary calcium excretion of more than 300 mg/24 h for men and 250 mg for women or 4 mg/kg/day [19,23,26,28,29,32,35,36,38,42,43]. The subjects were on a free or normal calcium diet in some studies [10,11,19,21,22,26,28,29,32,35,36,39,43], while restricted calcium diets were adopted in some others [24,27,…”

“…Seventeen studies described their criteria of hypercalciuria and they were not consistent [18,19,20,22,24,26,28,29,32,35,36,37,38,42,43,45], twelve of which defined hypercalciuria as urinary calcium excretion of more than 300 mg/24 h for men and 250 mg for women or 4 mg/kg/day [19,23,26,28,29,32,35,36,38,42,43]. The subjects were on a free or normal calcium diet in some studies [10,11,19,21,22,26,28,29,32,35,36,39,43], while restricted calcium diets were adopted in some others [24,27,31,33,34,38]. Nineteen of the included trials only tested serum/plasma 1,25(OH) 2 D [19,20,22,24,26,27,28,30,31,32,33,34,35,36,37,38…”