Rickets is caused by deficient mineralization at the level of growth plate and is usually due to a decreased serum calcium/phosphate product. Although the diagnosis of rickets can usually be suspected on the basis of a clinical examination (bone deformities in legs, impaired growth), radiological examination and detailed biochemical work-up are necessary to elucidate the etiology of the underlying disease. It is important to differentiate between calcipenic/vitamin deficient and phosphopenic rickets. The former is due to vitamin D deficiency, and the ultimate cause of this usually lies in altered vitamin D supply; however, impaired synthesis of or resistance to the actions of vitamin D can also be a cause. Phosphopenic rickets is usually related to impaired phosphate reabsorption in the proximal renal tubule. Both calcipenic and phosphopenic rickets can be acquired or hereditary in origin.