Many children’s calves are a little bent until the age of 2 and then grow straight. Some children appear to have some degree of pronation. Typically, this disappears after age 7. Both O-legs and cleavage are small deviations from normal and do not require treatment. The use of braces, orthopedic shoes, and special training are generally not helpful and may even hinder the child’s physical development and cause unnecessary psychological stress. Very rarely, O-legs or inward curves are caused by disease and need to be treated by a doctor. Vitamin D deficiency rickets can cause O-shaped legs, so be sure to take a preventive dose of vitamin D, 400 units per day, before age 3.