Vitamin D Deficiency Health Article

When to call the doctor

The doctor should be called if the parent notices that the child has any signs of vitamin D deficiency or rickets. Such signs include skeletal pain, bowed limbs, and impaired growth. If there are lifestyle factors that make the child at risk for vitamin D deficiency, such as low milk or formula intake, a doctor should be consulted about the possibility of using vitamin D supplements.

Diagnosis

Vitamin D deficiency is diagnosed by measuring the level of 25-hydroxy-vitamin D in the blood serum. The normal concentration of this form of vitamin D ranges from 25 to 50 ng/ml. Deficiency occurs when this level decreases to about 12 ng/ml or less.

Rickets is diagnosed by x-ray examination of the leg bones. A distinct pattern of irregularities, abnormalities, and a coarse appearance can be clearly seen if a child has rickets. Measurements of blood plasma 25-OH-D, blood plasma calcium, and blood plasma parathyroid hormone must also be obtained for the diagnosis of this disease. Parathyroid hormone and 1,25-diOH-D work together in the body to regulate the levels of calcium in the blood.

Treatment

Rickets heals promptly with large doses vitamin D administered orally each day for approximately one month. During this treatment, the doctor should monitor the levels of 25-OH-D in the plasma to make sure that they are raised to a normal level. The bone abnormalities (visible by x ray) generally disappear gradually over a period of three to nine months. Parents are instructed to take their infants outdoors for approximately 20 minutes per day with their faces exposed. Children should be encouraged to play outside and to eat foods that are good sources of vitamin D. These foods include cod liver oil, egg yolks, butter, oily fish and also foods, including milk and breakfast cereals, that are fortified with synthetic vitamin D.

Care must be taken in treating vitamin D deficiency, since high doses of vitamin D are toxic (poisonous) and can result in the permanent deposit of minerals in the heart, lungs, and kidneys. Symptoms of toxicity are nausea, vomiting, pain in the joints, and lack of interest in eating food. In adults, vitamin D toxicity occurs with eating 50,000 IU or more per day. In infants, toxicity occurs with 1,000 IU per day. The continued intake of toxic doses results in death.

Rickets are usually treated with oral supplements of vitamin D, with the recommendation to acquire daily exposure to direct sunlight. An alternative to sunlight is the use of an ultraviolet lamp. When people use UV lamps, they need to cover their eyes to protect them against damage. Many types of sunglasses allow UV light to pass through, so only those that are opaque to UV light should be used. Attempts to acquire sunlight through glass windows fail to help the body make vitamin D because UV light does not pass through window glass.

Rickets may also occur with calcium deficiency, even when a child is regularly exposed to sunshine. This type of rickets has been found in various parts of Africa. The bone deformities are similar to, or are the same as, those that occur in typical rickets; however, calcium deficiency rickets is treated by increasing the amount of calcium in the diet. No amount of vitamin D can cure the rickets of a child with a diet that is extremely low in calcium. For this reason, it is recommended that calcium be given in conjunction with vitamin D supplementation.