Vitamin K and childhood cancer: a population based case-control study in Lower Saxony, Germany

To confirm or refute a possible association of parenteral vitamin K prophylaxis and childhood cancer.

Population based case-control study. Comparison of vitamin K exposure in children with leukaemia or other common tumours with two control groups.

State of Lower Saxony (north western part of Germany); case recruitment from the German childhood cancer registry.

272 children with leukaemia, nephroblastoma, neuroblastoma, rhabdomyosarcoma, and tumours of the central nervous system diagnosed between 1 July 1988 and 30 June 1993; children were aged between 30 days and 15 years at diagnosis. 334 population based controls without diagnoses of cancer matched to the leukaemia cases for age and sex.

Parenteral vitamin K prophylaxis (intramuscular and subcutaneous) versus oral and no vitamin K prophylaxis.

An association between parenteral vitamin K exposure and childhood cancer (leukaemias and other tumours combined) could not be confirmed (odds ratio 1.04, 95% confidence interval 0.74 to 1.48). For leukaemias the observed odds ratio was only 0.98 (0.64 to 1.50) (comparison of leukaemia cases with local controls 1.24 (0.68 to 2.25); state controls 0.82 (0.50 to 1.36)). These odds ratios remained almost unchanged when several potential confounders were considered in the logistic regression model.

This population based study adds substantial evidence that there is no association between parenteral vitamin K and childhood cancer.