Vitamin D Status and Indices of Mineral Homeostasis in the Population: Differences Between 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin D

Abstract

Opinions are conflicting about the epidemiology of vitamin D deficiency. This population-based study investigated cross-sectionally the associations of 25-hydroxyvitamin D (calcidiol) and 1,25-dihydroxyvitamin D (calcitriol) with indices of mineral homeostasis. Study cohort consisted of 979 persons of the Moli-Sani study, both sexes, ages ≥35 years. Data collection included serum calcidiol by different assays, serum calcitriol, serum parathyroid hormone, serum and urine calcium, and phosphorus. Prevalence of mild-to-moderate calcidiol deficiency (10–19 ng/mL) was 36.4% and did not associate with hypocalcemia or hyperparathyroidism. Prevalence of severe calcidiol deficiency (<10 ng/mL) was 16.8% and associated with hyperparathyroidism only (odds ratio = 8.81, 95% confidence interval = 2.4/32.9). Prevalence of calcitriol deficiency (<18 pg/mL) was 3.1% and associated with hypocalcemia (29.1, 7.4/114.5) but not hyperparathyroidism. In ANOVA along concentration strata, lower calcidiol associated with higher parathyroid hormone only (p < 0.001). Lower calcitriol associated with lower serum and urine calcium (p < 0.001) but not with parathyroid hormone. Calcidiol findings were consistent with different calcidiol assays. In the population, mild-to-moderate calcidiol deficiency did not associate with abnormal mineral homeostasis. Severe calcidiol deficiency and calcitriol deficiency associated with different disorders: lower calcidiol associated with hyperparathyroidism whereas lower calcitriol associated with hypocalcemia and low urine calcium.

25-Hydroxyvitamin D, 1,25-Dihydroxyvitamin D, and Peripheral Bone Densitometry in Adults with Celiac Disease

“…The lack of association between 25(OH)D deficiency and low BMD was in accordance with data reported in the general population [42,43]. The finding that 25(OH)D deficiency was not associated with low serum calcium or low serum phosphorous but only with high serum PTH ws also in accordance with the data in the general population [13].…”

“…Given that this is the first study using recalibrated assay for 25(OH)D in CeD, data for recalibrated 25(OH)D could not be compared to previous CeD data but only to general population data, in which a similar overestimate of mild-to-moderate 25(OH)D deficiency was reported for nonrecalibrated assay [13]. The lack of association between 25(OH)D deficiency and low BMD was in accordance with data reported in the general population [42,43].…”

“…Serum 25(OH)D and 1,25(OH) 2 D were measured by chemiluminescent assay (Diasorin, Saluggia, Italy) [21]. As previously reported [13], and in accordance with a consensus report [22], the 25(OH)D chemiluminescent assay was recalibrated using the NIST-SRM 972a as the gold standard, that is, a product containing two levels of 25(OH)D certified by isotope dilution liquid mass chromatography (ID-LC-MS) and isotope dilution liquid chromatography-tandem mass spectrophotometry (ID-LC-MS/MS) [23]. Thus, the paper reported two sets of 25(OH)D data: Data obtained using the assay-specific calibration (defined as "nonrecalibrated data") and data collected after recalibration with NIST-SRM 972a product (defined as "recalibrated data").…”

Reduced Kidney Function and Relative Hypocalciuria—Observational, Cross-Sectional, Population-Based Data

“…Lab tests for the whole cohort included the measurements of serum cystatin C [ 15 ]. Target cohort for the present analysis was a sub-group of 1000 examinees of the Moli-sani study that were selected by a sex- and age- stratified randomization for additional lab tests using frozen samples of serum and urine [ 16 ]. The stratification was designed to have 100 men and 100 women for each one of the following five age-groups: 35–44, 45–54, 55–64, 65–74, and ≥75 years.…”

“…The stratification was designed to have 100 men and 100 women for each one of the following five age-groups: 35–44, 45–54, 55–64, 65–74, and ≥75 years. Additional lab tests included the measurements of the urine concentrations of creatinine, Ca, and phosphorus, and the measurements of serum concentrations of creatinine, total Ca, albumin, phosphorus, total 25-hydroxy-vitamin D [25(OH)D], PTH, and 1,25(OH) 2 D [ 16 ]. Automated biochemistry was used for the measurements of serum creatinine, Ca, albumin, phosphorus, PTH and for the measurements of urine creatinine, and Ca (Abbott, IL, USA) [ 16 , 17 ].…”