Rickets occurs at approximately six months of age in children who are vitamin D deficient. They can present with growth retardation, skeletal deformities including bowing of the legs or knocked knees, prominent knob like projections along the ribs next to the sternum known as the rachitic rosary and muscle weakness. Infants with vitamin D deficiency also suffer from craniotabes which is a softening of the skull causing it to become square shaped. They can have increase in the bone formation in the front of the head which is known as frontal bossing.
