RT Journal Article SR Electronic T1 Vitamin D and parathyroid hormone and bone mineralisation in adults with cystic fibrosis. JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 190 OP 194 DO 10.1136/thx.43.3.190 VO 43 IS 3 A1 R J Stead A1 S Houlder A1 J Agnew A1 M Thomas A1 M E Hodson A1 J C Batten A1 P Dandona YR 1988 UL http://thorax.bmj.com/content/43/3/190.abstract AB Vitamin D and parathyroid hormone concentrations were assessed in 31 adults with cystic fibrosis (mean age 24, range 17-52 years), in 28 of whom the bone mineral index in the forearm was also determined. Serum 25-hydroxyvitamin D was subnormal in eight patients, of whom five were receiving vitamin D supplements in standard doses. 1,25-dihydroxyvitamin D and parathyroid hormone concentrations showed no consistent abnormalities. The bone mineral index was lower in patients with cystic fibrosis (p less than 0.02) than in controls. Five patients with unequivocally reduced bone mineral index had a subnormal mean serum 25-hydroxyvitamin D and significantly worse lung function than the other patients. There was a positive correlation between age and bone mineral index (r = 0.68, p less than 0.001). Thus a significant proportion of patients with cystic fibrosis living in a temperate climate are at risk of vitamin D deficiency. Osteopenia is common and is probably related to a combination of hypovitaminosis D, delay in puberty, hypo-oestrogenism in women, and reduced physical activity, rather than to secondary hyperparathyroidism. Since most patients with deficiency of 25-hydroxyvitamin D were receiving oral supplements, parenteral vitamin D supplementation may be appropriate for selected patients who are unable to maintain adequate 25-hydroxyvitamin D concentrations despite oral vitamin D supplements.