Increased 1,25-(OH)2D2 concentration in a patient with malignancy-associated hypercalcemia receiving intravenous hyperalimentation inadvertently supplemented with vitamin D2.
A 55-year-old patient with hypercalcemic crisis due to gastric carcinoma with bone marrow metastasis was treated with bisphosphonate (pamidronate) and calcitonin. Urinary excretion of parathyroid hormone-related protein (PTHrP) was increased. When normocalcemia had been attained, intravenous hyperalimentation was started, in which 1,000 U vitamin D2 was inadvertently supplemented on days 5-18, On days 15-18, hypercalcemia rapidly recurred, accompanied by markedly increased serum levels of 25-OHD2 (9.1 ng/dl) and 1,25-(OH)2D2 (161 pg/ml). This clinical course suggests that PTHrP, like PTH, stimulated 1 alpha-hydroxylase activity and produced excessive 1,25-(OH)2D2. Vitamin D should not be administered to patients with malignancy-associated hypercalcemia, particularly that due to PTHrP-producing tumors.
Sato
K
K
Department of Medicine, Tokyo Women's Medical College.
Imaki
T
T
Toraya
S
S
Demura
H
H
Tanaka
M
M
Kasajima
T
T
Takeuchi
A
A
Kobayashi
T
T
D002117:Calcitriol / Q000097:blood*; D000075202:Contraindications; D004164:Diphosphonates / Q000627:therapeutic use; D004872:Ergocalciferols / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D006934:Hypercalcemia / Q000097:blood* / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis; D000077268:Pamidronate; D010281:Parathyroid Hormone / Q000096:biosynthesis; D044162:Parathyroid Hormone-Related Protein; D010289:Parenteral Nutrition, Total / Q000009:adverse effects; D014176:Protein Biosynthesis; D013274:Stomach Neoplasms / Q000150:complications / Q000378:metabolism / Q000628:therapy
D004164:Diphosphonates; D004872:Ergocalciferols; D009363:Neoplasm Proteins; C470121:PTHLH protein, human; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D002117:Calcitriol; D000077268:Pamidronate