Rickets may be diagnosed with the help of: Blood tests: Serum calcium may show low levels of calcium, serum phosphorus may be low, and serum alkaline phosphatase may be high from bones or changes in the shape or structure of the bones. This can show enlarged limbs and joints. A bone density scan may be undertaken. Radiography typically show widening of the zones of provisional calcification of the metaphyses secondary to unmineralized osteoid. Cupping, fraying, and splaying of metaphyses typically appears with growth and continued weight bearing. These changes are seen predominantly at sites of rapid growth, including the proximal humerus, distal radius, distal femur and both the proximal and the distal tibia. Therefore, a skeletal survey for rickets can be accomplished with anteroposterior radiographs of the knees, wrists, and ankles. In veterinary practice, rickets, osteodystrophy and mineral metabolism disorders are diagnosed using an ultrasound echosteometer in the design М.М. Orlov and А.V. Savinkov. Types Vitamin D-related rickets Vitamin D deficiency Vitamin D-dependent rickets (VDDR) Type 1: insufficiency in activation VDDR1A: 25-Hydroxyvitamin D3 1-alpha-hydroxylase deficiency VDDR1B: CYP2R1 deficiency Type 2: resistance to calcitriol VDDR2A: calcitriol receptor mutation VDDR2B: unknown nuclear ribonucleoprotein interfering with signal transduction Type 3: excessive inactivation (CYP3A4 mutation, dominant) Hypocalcemia-related rickets Hypocalcemia Chronic kidney failure (CKD-BMD) Hypophosphatemia-related rickets Congenital Vitamin D-resistant rickets Autosomal dominant hypophosphatemic rickets (ADHR) Autosomal recessive hypophosphatemic rickets (ARHR) Hypophosphatemia (typically secondary to malabsorption) Fanconi's syndrome Secondary to other diseases Tumor-induced osteomalacia McCune-Albright syndrome Epidermal nevus syndrome Dent's disease Differential diagnosis Osteochondrodysplasias, also known as genetic bone diseases, may mimic the clinical picture of rickets in regard to the features of bone deformities. The radiologic picture and the laboratory findings of serum calcium, phosphate and alkaline phosphatase are important differentiating factors. Blount's disease is an important differential diagnosis because it causes knee deformities in a similar fashion to rickets namely bow legs or genu varum. Infants with rickets can have bone fractures. This sometimes leads to child abuse allegations. This issue appears to be more common for solely nursing infants of black mothers, in winter in temperate climates, suffering poor nutrition and no vitamin D supplementation. People with darker skin produce less vitamin D than those with lighter skin, for the same amount of sunlight. Treatment Diet and sunlight Treatment involves increasing dietary intake of calcium, phosphates and vitamin D. Exposure to ultraviolet B light (most easily obtained when the sun is highest in