25-hydroxyvitamin-d-2 and Liver-Diseases

Topics: 24,25-Dihydroxyvitamin D 3; 25-Hydroxyvitamin D 2; Animals; Calcitriol; Calcium; Chick Embryo; Dihydroxycholecalciferols; Dogs; Ergocalciferols; Female; Humans; Kidney Diseases; Liver Diseases; Pregnancy; Vitamin D; Vitamin D Deficiency

Twenty-nine patients with chronic liver disease, nine of whom had symptoms suggesting bone disease, were studied by bone histology. Nine had osteomalacia; six associated with cholestatic liver disease and three with primarily hepatocellular disease. Two of these had clinical and biochemical features of cholestasis for at least a year and the other had alcoholic cirrhosis associated with severe malnutrition. Excluding the latter patient, histological osteomalacia was significantly associated with presence and duration of cholestasis. Plasma 25-hydroxyvitamin D was low and fasting urine hydroxyproline/creatinine ratio was high in all patients with osteomalacia but were abnormal also in some patients who did not have histological osteomalacia. Serum calcium, phosphate, alkaline phosphatase, vitamin D-binding protein and radiology were unhelpful in many patients with osteomalacia. Vitamin D-deficiency correlated significantly with deficiency of other fat-soluble vitamins and those patients with rachitic levels of plasma 25-hydroxyvitamin D showed no seasonal variation, suggesting a combination of malabsorption of vitamin D and reduced sunlight exposure. We suggest that patients with chronic liver disease with cholestasis for at least a year are at risk from osteomalacia and that those likely to have this complication may be identified by plasma 25-hydroxyvitamin D and/or fasting urine hydroxyproline/creatinine ratio measurements. The diagnosis can only be made with certainty by bone biopsy.

Topics: 25-Hydroxyvitamin D 2; Adolescent; Adult; Aged; Cholestasis; Chronic Disease; Ergocalciferols; Humans; Liver Diseases; Middle Aged; Osteomalacia; Risk; Seasons; Vitamin D Deficiency

Previous reports have suggested that secondary hyperparathyroidism is extremely uncommon in hepatic osteomalacia. This, together with other findings, has led to suggestions that in chronic liver disease there may be selective resistance of bone to vitamin D or a specific bone mineralization defect unrelated to Vitamin D. To examine these possibilities, twenty-five patients with chronic liver disease have been studied by bone biopsy, serum calcium and inorganic phosphate, plasma 25-hydroxyvitamin D, plasma immunoreactive parathormone (iPTH), fasting urine cAMP, fasting renal tubular maximal reabsorptive capacity for phosphate (TmP/GFR) and fine grain hand x-rays. Nine of the patients had osteomalacia on bone biopsy, eight of these had subnormal levels of plasma 25-hydroxyvitamin D and the other had a borderline result. Based on the consensus of all the tests, five of these had evidence of secondary hyperparathyroidism. Plasma iPTH was higher in patients with osteomalacia than in patients without osteomalacia (P less than 0.01) or controls (P less than 0.01). Urine cAMP was higher in patients with osteomalacia than in patients without osteomalacia (P less than 0.001) or controls (P less than 0.01). TmP/GFR was significantly lower in patients with osteomalacia than in controls (P less than 0.05) but not significantly different from patients without osteomalacia. The findings of this study indicate that hyperparathyroidism occurs in a substantial proportion of patients with the osteomalacia of chronic liver disease. Moreover, osteomalacia in chronic liver disease is clearly related to reduced levels of plasma 25-hydroxyvitamin D. We conclude that hepatic osteomalacia is a vitamin D deficiency state and there is no need to suggest an unusual aetiology.

Topics: 25-Hydroxyvitamin D 2; Chronic Disease; Cyclic AMP; Ergocalciferols; Humans; Hyperparathyroidism, Secondary; Liver Diseases; Osteomalacia; Parathyroid Hormone