Perspective on Assessment of Vitamin D Nutrition

Although routine fortification of milk and a few other dairy products has been successful in preventing rickets in children, its impact on preventing vitamin D depletion in adults is less than satisfactory. The prevalence of vitamin D depletion in the elderly is on the rise again and appears to be more common than is currently appreciated. Several groups of individuals are at risk of developing vitamin D depletion, and a significant minority of otherwise healthy individuals is vitamin D insufficient. Unrecognized vitamin D depletion leads to secondary hyperparathyroidism, accelerates cortical bone loss, and increases the risk of hip fractures. With the availability of techniques to assess vitamin D nutrition, it is probably cost effective to routinely measure 25-hydroxyvitamin D levels in individuals at the greatest risk and in patients with various metabolic bone diseases to prevent vitamin D depletion. Early recognition and prompt treatment of vitamin D depletion improves functional well being of the individual, reduces morbidity related to bone loss and fractures, and is associated with a highly favorable cost/benefit ratio.     

磷酸盐尿性间叶肿瘤误诊分析(附7例)

目的:分析磷酸盐尿性间叶肿瘤(PMT)误诊原因,明确影像学检查路径。方法:回顾性分析我院2017年7月至2022年3月经病理证实PMT患者临床、影像、病理资料。结合文献复习,总结误诊原因,提出影像学检查路径。结果:7例患者3例男性,4例女性,平均年龄为(50.29±15.66)岁(范围17～69岁)。患者表现为不同程度乏力、骨痛等,均伴随骨折,病程平均(5.00±3.25)年(范围1～12年)。患者术前血磷均减低,术后血磷均升高,6例患者血磷在术后7～15天恢复正常,1例失访。6例患者术前碱性磷酸酶升高,1例正常。肿瘤最大径(2.01±1.32)cm(范围0.8～2.5 cm),2例位于软组织,5例位于骨组织。6例行X线检查,显示全身或局部骨质不同程度骨软化和伴随骨折,3例病灶无法显示。6例CT检查中5例骨组织病灶显示为高密度,1例为软组织密度结节。6例MRI平扫T1WI为低、等信号为主,偶尔见高信号,T2WI混杂高信号,内部或边缘可见低信号区。4例MRI增强检查显示病灶中度至明显强化,强化不均匀。结论:PMT影像表现缺乏特异性,容易被误诊。骨质软化、骨痛、骨折以及低血磷、高碱性磷酸酶...     

Determination of the bioavailability of intranasal elcatonin in humans: Development of a sandwich transfer enzyme immunoassay for elcatonin

A sandwich transfer enzyme immunoassay for elcatonin (ECT) and its usability for the pharmacokinetic study are described. The anti-salmon calcitonin (SCT) antibody was used for the present assay. The assay procedure consisted of the reaction of ECT with 2,4-dinitrophenylbiotinyl anti-SCT IgG and anti-SCT Fab′-β-D -galactosidase conjugate, trapping onto (anti-2,4-dinitrophenyl bovine serum albumin) IgG-coated polystyrene balls, eluting with ϵN-2,4-dinitrophenyl-L-lysine and transferring to streptavidin-coated polystyrene balls and fluorometric detection of β-D -galactosidase activity. The practical detection limit of ECT was 0.15 pg (44 amol)/50 μl of sample and 3 pg/ml as the concentration. The application of this method has enabled us to directly estimate the bioavailability of ECT dosed intranasaly at a therapeutic level (100 IU, 17 μg) for its anti-osteoporotic effect as compared to an intramuscular dose (40 IU, 6.7 μg). The pharmacokinetic parameters of the intranasal ECT (n = 6) thus estimated were as follows: the area under the serum concentration-time curve (AUC) = 2,570 ± 1,650 (SD) pg × min/ml, and the maximal concentration (Cmax) = 60 ± 25 (SD) pg/ml with the maximal time (Tmax) = 17.5 ± 6.9 (SD) min, when the AUC for the intramuscular ECT (n = 9) = 9,460 ± 5,870 (SD) pg × min/ml and the Cmax = 165 ± 79 (SD) pg/ml with the Tmax = 16.1 ± 4.2 (SD) min. J. Clin. Lab. Anal. 12:356–362, 1998. © 1998 Wiley-Liss, Inc.     

Vitamin D deficiency osteomalacia triggered by long-term social withdrawal and unbalanced diet in a Japanese middle-aged subject: A case report

Introduction:Osteomalacia is caused by an increase in the number of osteoids owing to mineralization failure. There are various causes of osteomalacia, such as hypophosphatemia due to excess production of fibroblast growth factor 23, vitamin D deficiency, insufficient vitamin D action, and renal tubular disorders.Patient concerns:A 53-year-old man with bone pain and gait disturbance was referred to our institution. At the age of 35, he developed atopic dermatitis. He had eyesight deterioration due to atopic cataracts when he was 37 years old. Subsequently, he stayed home all the time, and his eating habits were unbalanced for a long period of time. Although he had atopic dermatitis, he did not take allergen-free diets, and he did not use sunscreen. Furthermore, when he was 43 years old, he failed to flex his legs and suffered gait disturbance.Diagnosis:Hypocalcemia and hypophosphatemia were observed as follow: calcium, 5.5 mg/dL; adjusted calcium, 6.9 mg/dL; inorganic phosphorous, 1.9 mg/dL. In addition, intact parathyroid hormone levels were as high as 277.4 pg/mL, and 1, 25-(OH)₂ vitamin D and 25-(OH) vitamin D levels were markedly reduced: 1, 25-(OH)₂ vitamin D, ≤4 pg/mL; 25-(OH) vitamin D, 11.0 ng/mL. Fibroblast growth factor 23 levels did not increase. Alkaline phosphatase (ALP) and bone-type ALP (BAP) levels were high: ALP, 784 U/L; BAP, 159.2 μg/L (reference range: 3.7–20.9 μg/L). Based on these findings, we diagnosed this patient with vitamin D-deficient osteomalacia triggered by long-term social withdrawal and an unbalanced diet.Interventions and outcomes:After hospitalization, to treat vitamin D-deficient osteomalacia, we started to administer 1 μg/day of alfacalcidol and 3 g/day of calcium lactate. Approximately one month later, 1,25-(OH)₂ vitamin D levels increased to 214 pg/mL. Consequently, calcium and inorganic phosphorus were also increased up to 7.8 mg/dL and 3.9 mg/dL, respectively, and intact parathyroid hormone was decreased to 132.0 pg/mL.Conclusions:We should bear in mind the possibility of osteomalacia triggered by social withdrawal and vitamin D deficiency even in middle-aged subjects.     

散发性低磷血性骨软化症临床及影像学表现

目的 观察散发性低磷血性骨软化症(HO)的临床及影像学表现。方法 回顾性分析19例散发性HO患者，观察其临床及影像学表现。结果 19例散发性HO患者首发症状均为不同程度骨痛及肌无力；19例均见低磷血症，9例血钙降低，16例碱性磷酸酶(ALP)升高，4例甲状旁腺激素(PTH)升高，7例24 h尿钙(UCa)升高、2例降低，18例24 h尿磷(UP)降低、1例升高。X线片示11例骨质疏松、6例退变、6例骨折；全身骨扫描示18例全身多发局部骨代谢活跃灶；骨密度双能X线吸收测定法扫描(DEXA)示16例患侧髋关节骨质疏松、3例骨量减少，8例脊柱区域骨质疏松、11例骨量减少；MRI示11例双侧股骨头关节面下条形T1低信号，脂肪抑制序列呈高信号；8例胸腰椎体上、终板下条片状双低信号，脂肪抑制序列见周围骨质片状稍高信号，呈“夹心板”征。结论 散发性HO以全身多部位不同程度骨痛和肌无力为主要临床表现，伴低血磷、低UP及高ALP等；影像学可见骨质密度异常、横向假骨折线、软骨下细微骨折及“夹心板”征等改变。     

Tumor induced osteomalacia from a peripheral mesenchymal tumour of the foot

Tumour induced osteomalacia (TIO) is a rare condition caused by peripheral mesenchymal tumours (PMT) which produce fibroblast-growth factor 23 (FGF23). FGF23 inhibits renal phosphate reabsorption leading to vitamin D resistant osteomalacia. The rarity of the condition and difficulty with isolating the PMT make diagnosis difficult, with delayed treatment leading to significant patient morbidity. We present a case of PMT of the foot with TIO, with a discussion on diagnosis and treatment.