To evaluate the measured free 25-hydroxyvitamin D [25(OH)D] levels in patients with hyperparathyroidism (PHPT) and healthy controls. Eighty patients with PHPT(n = 40) and age and BMI matched controls (n = 40) were examined. Serum levels of total or free 25(OH)D, vitamin D binding protein (DBP), intact parathyroid hormone (iPTH) and calcium were measured. There was no significant difference in age (61.2 ± 11.9 vs 60.2 ± 7.0 years) and BMI (30.0 ± 6.1 vs 30.0 ± 2.2 kg/m2) between PHPT patients and healthy subjects. Levels of total 25(OH)D were about 20 % lower in PHPT patients (26.4 ± 7.7 ng/mL) compared to controls (31.0 ± 7.8 ng/mL, P < 0.05). There were no significant differences in calculated or measured free 25(OH)D levels between PHPT patients (4.9 ± 1.8 or 4.9 ± 1.6 pg/mL, respectively) and control subjects (5.1 ± 1.2 or 5.3 ± 1.6 pg/mL, respectively). Levels of free 25(OH)D were positively associated with levels of total 25(OH)D (r = 0.28, P < 0.05) but negatively correlated with iPTH and calcium levels (r=-0.22 and -0.23 respectively, P < 0.05). Serum total 25(OH)D levels were lower but the calculated or measured free 25(OH)D levels in patients with PHPT did not differ from healthy subjects. We suggest that total 25(OH)D levels may not reflect true vitamin D nutritional status in patients with PHPT.

中文翻译：

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原发性甲状旁腺功能亢进症患者的总25-羟基维生素D降低，但计算或测得的游离25-羟基维生素D血清水平无差异。

为了评估甲状旁腺功能亢进症（PHPT）患者和健康对照者体内测得的游离25-羟基维生素D [25（OH）D]水平。检查了80例PHPT（n = 40），年龄和BMI匹配对照（n = 40）的患者。测量血清中总或游离25（OH）D，维生素D结合蛋白（DBP），完整甲状旁腺激素（iPTH）和钙的水平。在PHPT患者和健康受试者之间，年龄（61.2±11.9 vs 60.2±7.0岁）和BMI（30.0±6.1 vs 30.0±2.2 kg / m2）没有显着差异。与对照组（31.0±7.8 ng / mL，P <0.05）相比，PHPT患者的总25（OH）D水平降低了约20％（26.4±7.7 ng / mL）。PHPT患者（分别为4.9±1.8或4.9±1.6 pg / mL）和对照组（5.1±1.2或5.3±1.6 pg / mL）的计算或测量的游离25（OH）D水平无显着差异，分别）。游离25（OH）D的水平与总25（OH）D的水平呈正相关（r = 0.28，P <0.05），而与iPTH和钙水平呈负相关（r = -0.22和-0.23，P <0.05 ）。患有PHPT的患者的血清总25（OH）D水平较低，但计算或测得的游离25（OH）D水平与健康受试者无差异。我们建议PHPT患者的总25（OH）D水平可能不能反映出真正的维生素D营养状况。