cholecalciferol and Bone-Diseases--Developmental

Bowing of the legs is common in childhood. Most times it is considered to be rickets without considering other possibilities. Blount´s disease is a close differential diagnosis which is developmental deformity characterized by intorsion of tibia leading to varus angulation. This case report aims to encourage pediatricians to expand their vision and consider other possibilities when a case of bowing of legs is encountered. Here we report a case of a four-year-old boy with bowing of both legs noticed first at 2.5 years of age. There was no history suggestive of trauma. Development of the child was age appropriate in all domains. He was receiving treatment for rickets for 1.5 years in form of oral vitamin D3 and calcium supplementations. He had no other clinical signs of rickets like frontal bossing, widening of wrists, and rachitic rosary except bowing of legs. His biochemical parameters did not show any alterations that would support the diagnosis of rickets. Weight-bearing radiographs of lower limbs showed medial intorsion of bilateral tibia with metaphyseo-diaphysial angle to be 25º on the right side and 20º on the left side, which was beyond the physiological normal angulation, therefore he was diagnosed as a case of Blount´s disease, stage III as per Langenskiöld classification. All the bow legs is not always rickets in pediatric practice. Therefore, various differential diagnoses should be kept in mind as early diagnosis and intervention can change a child´s life.

Topics: Bone Diseases, Developmental; Calcium; Child; Child, Preschool; Cholecalciferol; Genu Varum; Humans; Male; Osteochondrosis; Rickets; Tibia

Amounts of 25-hydroxycholecalciferol in plasma were measured in two groups (A and B) of lambs (Experiment 1) and in two groups (C and D) of wethers (Experiment 2). Groups A (eight lambs) and C (nine wethers) consisted of animals born and raised in total confinement; these animals exhibited an osteodystrophic condition. Groups B (four lambs) and D (10 wethers) consisted of healthy animals born and raised in a conventional barn with free access to an open barn yard (i.e. exposure to sunshine). The 25-hydroxycholecalciferol in plasma of both groups of sick animals, Group A (12.9 ng/ml) and Group C (18.0 ng/ml), were lower than the amounts of the two corresponding groups of healthy animals. Group B (29.2 ng/ml and Group D (32.5 ng/ml). Pharmacokinetic analysis of 25-hydroxycholecalciferol in affected lambs following intramuscular injection of 1,000,000 IU vitamin D3 indicated that transport of vitamin D3 from the site of injection to the liver and its metabolism to 25-hydroxycholecalciferol were rapid. Peak 25-hydroxycholecalciferol occurred at .6 wk, and half-life was 3.1 wk.

Topics: Animals; Biological Transport; Bone Diseases, Developmental; Cholecalciferol; Half-Life; Hydroxycholecalciferols; Kinetics; Liver; Male; Mathematics; Sheep

A bent-limb syndrome in lambs raised in total confinement was characterized by curvature of the forelimbs. Radiographic findings included flaring of the affected long bone and thinning of the growth plate. The main histologic change was endochondral dysplasia of the long bone. In feed samples, all trace minerals analyzed were within recommended concentrations except iron, which was much higher (400 ppm dry matter) than the normal requirement of lambs (70 ppm). All mineral concentrations in serum were normal except those of inorganic phosphorus and iron, which were higher. Results of soft tissue and bone mineral analyses were normal. Altering the ratio of calcium and phosphorus did not affect the incidence of disease, but intramuscular administration of massive doses of vitamin D3 and reducing the amount of dietary iron had a prophylactic effect. The increase in serum phosphorus was probably related to the dietary excess of iron, which probably decreased vitamin D metabolite formation in the kidney, which in turn could be prevented by massive doses of vitamin D3.

Topics: Animals; Bone Diseases, Developmental; Calcium; Cholecalciferol; Forelimb; Housing, Animal; Phosphorus; Sheep; Sheep Diseases