Threshold value of serum 25-hydroxyvitamin D concentration in relation to elevated serum parathyroid hormone concentrations in elderly Japanese women

Abstract

This study was designed to determine the threshold value for 25-hydroxyvitamin D [25(OH)D] concentration in relation to elevated serum parathyroid hormone (PTH) concentrations in elderly Japanese women. The subjects were 582 noninstitutionalized, ambulant women who lived in a community in Japan. Serum 25(OH)D concentrations were determined using the Nichols Advantage chemiluminescent assay, and serum intact PTH concentrations were determined with a two-site immunoradiometric assay. Demographic characteristics, calcium intake, and serum 1,25(OH)(2)D levels were also determined. The average age, body mass index (BMI), and calcium intake of the subjects were 74.5 years (SD 4.5), 23.3 kg/m(2) (SD 3.4), and 579 mg/day (SD 248), respectively. The serum log-transformed intact PTH concentration was significantly predicted by the serum 25(OH)D concentration (r = -0.147, P = 0.0004), but not by age, BMI, the serum log-transformed 1,25(OH)(2)D concentration, or the log-transformed calcium intake. Analysis of variance with Dunnett's multiple comparisons showed that mean serum intact PTH concentrations with serum 25(OH)D concentrations less than 30 nmol/l (mean intact PTH = 5.89 pmol/l, P < 0.0001) and in the range 30-39 nmol/l (mean intact PTH = 4.54 pmol/l, P = 0.0067) were significantly higher than mean intact PTH concentrations for serum 25(OH)D concentrations greater than 50 nmol/l (mean intact PTH = 3.65 pmol/l, the baseline level), but the mean serum intact PTH concentration for 25(OH)D concentrations in the range 40-49 nmol/l (mean intact PTH = 3.70 pmol/l, P = 0.9975) was not. We conclude that serum 25(OH)D for ambulant elderly Japanese women should be maintained at 40 nmol/l or higher.

Association of Leptin, 25-Hydroxyvitamin D, and Parathyroid Hormone in Women

“…Classification of vitamin D sufficiency and insufficiency is typically based on the observance of elevated PTH (20,45–47), at or around circulating 25-OH-VitD concentrations of less than 80 nM (30 ng/ml). The higher PTH levels observed with increasing deficiency of 25-OH-VitD in the current study are consistent with previous studies (45,48,49). Interestingly, circulating levels of leptin exhibited a similar pattern, increasing sharply below the deficiency level for 25-OH-VitD.…”

Vitamin D status in relation to obesity, bone mineral density, bone turnover markers and vitamin D receptor genotypes in healthy Saudi pre- and postmenopausal women

“…Moreover, serum 25(OH)D exhibited positive correlations with BMD values of the lumbar spine (L1-L4) and more significantly with that of neck femur even after adjustment for age and BMI; the latter observations were similar to that observed in other studies in both young [68][69][70][71][72] and elderly [9,73] women. In addition, several studies have demonstrated an inverse correlation between serum PTH levels and BMD, particularly at the femoral neck [44,49,74]; these studies showed that subjects with increased PTH levels in vitamin D insufficiency exhibited lower BMD values and higher bone turnover than subjects with decreased PTH levels.…”

Relationship of circulating levels of 25(OH) vitamin D with parathyroid hormone in Iranian patients with chronic kidney disease not yet on dialysis; what is the best threshold for 25(OH) vitamin D

“…This study also showed (20,21) or even in healthy subjects (22,23). Up to our best knowledge, there are plenty of studies which found negative correlation between serum PTH and 25(OH) vitamin D level, especially in the range of 10 to 50 ng/ mL (25-125 nmol/L) (24), but only few studies suggested a certain threshold for 25(OH) vitamin D to prevent secondary hyperparathyroidism (25,26), especially in adult patients with CKD (27). Some other studies also found this relation more complex and related to age and ethnicity of CKD patients (28,29).…”