Lactose malabsorption and calcium intake as risk factors for osteoporosis in elderly New Zealand women.

OBJECTS

to evaluate the prevalence of lactose malabsorption and to assess dietary calcium intake, in elderly New Zealand women with hip fractures, in age matched case controls without hip fractures drawn from general practice, and in healthy young women.

METHODS

lactose malabsorption was assessed by measuring breath hydrogen after a 50 g oral lactose tolerance test. Dietary calcium was estimated from a food frequency questionnaire.

RESULTS

the elderly fracture cases (n = 15), and their elderly controls (n = 16), showed a similar (60% and 63% respectively), but significantly higher prevalence (p less than 0.001), of lactose malabsorption than young women (12%, n = 50). Dietary calcium intake was similar in lactose absorbers and malabsorbers.

CONCLUSIONS

malabsorption of lactose occurs commonly in elderly New Zealand women but is scarce in young adults. A high prevalence of lactose malabsorption may be a risk factor for exacerbation of type II osteoporosis in the elderly.