Low Body Mass Index (BMI) is a risk factor for hip fracture, but it is unknown if it is the low BMI per se that increases risk of hip fracture or if specific micro-nutrients contribute. The investigators want to elucidate this aspect in a case control study studying micronutrients in serum and bone turnover markers of hip fracture patients compared with controls of the same age.

Inclusion Criteria:

Cases are admitted acutely for a femoral neck fracture, a trochanteric or a subtrochanteric femoral fracture.

Exclusion Criteria:

• Hip fracture as part of multi-trauma or high energy trauma (defined as a fall from a higher level than 1 metre). One recent fracture in addition to the hip fracture (e.g. radius or shoulder) is acceptable.
• Regarded as moribund at admittance.
• Absence of a valid informed consent or assent.

Cases: The first 116 patients of an ongoing RCT were included consecutively and examined by blood samples pre operatively for nutrition and hormone analysis. The catchment area for the cases was the city of Oslo, Norway.

A control group, at the same age with no history of hip fracture, was drawn at random from inhabitants aged 60 - 100 years (median age 82 years) at the census files of Oslo in 2005.