Occasionally, vitamin D metabolite preparations, such as calcitriol or dihydrotachysterol, are needed. Since patients with Lowe syndrome may be predisposed to developing kidney calcifications even without vitamin D metabolite therapy, the kidneys should be checked for this condition by ultrasound or x-ray before starting, and at intervals during, any therapy with vitamin D metabolites. All medications and dosages must be individualized for each child by his physician. Blood and urine tests and X-rays are usually ordered periodically. Blood tests may be done to measure calcium, phosphorus, bicarbonate, alkaline phosphatase, vitamin D metabolites, and parathyroid hormone.
Alkaline phosphatase is an enzyme made in bone.
When the bone is actively breaking down as in rickets, or when the bone is actively growing and forming new bone as during healing of rickets, the blood level of alkaline phosphatase will be elevated. The 25-hydroxy vitamin D level indicates whether the dietary intake of vitamin D is adequate, while the calcitriol level indicates whether the kidney is making adequate amounts of this substance for bone growth and prevention of rickets. Parathyroid hormone is a hormone made in a gland in the neck near the thyroid. Parathyroid hormone regulates calcium levels in the body and may be elevated when a patient has rickets or is receiving too much phosphorus supplementation. Urine tests may be done to measure phosphorus, calcium, albumin, creatinine, and pH and will indicate the severity of the urinary losses of calcium, phosphorus, albumin, and bicarbonate.