 [ Symptoms ] what is rickets [ Disease ] rickets is a disease caused from a critical lack of vitamin d that leads to a lack of calcium and phosphorus and eventually the softeningweakening of the bones since the absorption of vitamin d is dependent on sunshine rickets is more common in countries that receive little sunshine and where the diet may be deficient in this essential vitamin in the u s and other modern countries where many of our foods and milk is vitamin d fortified rickets is rare