营养性维生素D缺乏性佝偻病.pptVIP

rickets of vitamin D deficiency (营养性维生素D缺乏性佝偻病) Rickets is a very common nutritional deficient disease in young children especially under two years old of age. VitD deficiency cause rickets, a metabolic disorder of calcium and phosphorus with a failure to mineralize osteoid tissue of growing bone resulting in bony deformities UV Vit D (VitD3 VitD2 ) Parathyroid hormone （PTH）甲状旁腺素 Bone: stimulates decalcification （脱钙）of old bone but inhibit calcification (钙化) of new bone. Intestine: enhances absorption of Ca and P. Kidney: stimulates renal tubular reabsorption of Ca but loss of P. Calcitonin (CT) 降钙素 Vitamin D–deficient rickets can be conceptualized as the bodys attempt to maintain normal serum calcium levels，which results in halted bone mineralization 1、Ca×P↓，成熟软骨细胞、成骨细胞不能钙化，继续增殖，骨样组织堆积于干骺端→临时钙化带增厚，形成肋串珠、手、脚镯征 2、Ca×P↓，骨膜下成骨活动发生障碍→骨皮质为不坚硬的骨样组织代替→颅骨软化；骨样组织堆积→方颅 3、骨干骨化障碍→骨质疏松，易受肌肉、韧带牵拉和重力的作用→鸡胸、郝氏沟、O、X型腿、病理性骨折 4、骨骼生长最迅速的部位，其骨骼病变最显著 4 . X-ray : temporary calcified zone (临时钙化带) may be normal or become clouding (稍模糊) . 5 . Biochemical change : Ca normal or↓, P↓, 25-（OH）D3 ↓, PTH↑, ALP normal or ↑ . 脊柱——kyphosis 后凸, Scoliosis 侧弯 temporary calcified zone （钙化带 ）may disappear like brush（毛刷），cuppy （杯口）change 。 metaphyses（干骺端 ）broad. （2mm） osteoporosis（骨质疏松） Shaft curvature（弯曲）deformity or green stick fracture（青枝骨折）. ?粘多糖病 mucopolyasccharidosis ? 骨软骨营养不良 Achondroplasia ?脑积水 Hydrocephalus 骨软骨营养不良 Achondroplasia ? 低血磷抗维生素D佝偻病 hypophosphatemic VD resistant rickets 肾小管重吸收磷及肠道吸收磷的原发性缺陷 ? 远端肾小管性酸中毒 distal renal tubular acidosis 为远曲小管泌氢不足，从尿中丢失大量钠、钾、 钙，继发性甲状旁腺功能亢进 ? 维生素D依赖性佝偻病 VD depend