To assess the impact of a 12 month vitamin K supplementation intervention on bone health in adult Crohn's disease patients

To assess the impact of 12 months of vitamin K1 supplementation (plus vitamin D and calcium supplementation to avoid deficiency of these problematic nutrients) at a level which leads to dramatically (i.e greater than 70%) reduced levels of undercarboxylated osteocalcin - a functional marker of vitamin K status, on vitamin K status, the rate of bone formation and bone resorption, using biochemical markers of bone turnover, and bone mineral density in adult patients with longstanding Crohn's disease.

Inclusion Criteria:

• long-standing Crohn's disease - disease diagnosis > 5 years
• in clinical remission at baseline - Harvey-Bradshaw score (< 5)
• aged between 18-70 years

Exclusion Criteria:

• use of steroid medications to treat disease or flare up
• use of blood thinning medications (warfarin, heparin, asprin, dicoumarol derivatives) which may influence vitamin K metabolism
• use of bisphosphonates, calcitonin medications (to treat osteoporosis)
• use of experimental drugs (in the last 30 days) or inclusion in another intervention trial
• bone mineral density < -2.5 (indicative of osteoporosis) or previous diagnosis of osteoporosis
• use of vitamin/mineral/fish liver oil dietary supplements
• use of other alternative supplements (i.e herbal)
• if the patient is under 18 or over 70 years of age
• presence of a significant acute or chronic coexisting illness (cardiovascular, immunological or a condition which in the investigator's judgement, contraindicates involvement in the study)
• presence of malignant or any concomitant end-stage organ disease