OBJECTIVES: Our pilot study tested the efficacy, acceptability and tolerability of DHA supplementation in addition to calcium and vitamin D in individuals with osteopenia. STUDY DESIGN: 40 participants were randomised to either algal oil containing 400mg docosahexanoic acid (DHA) daily or placebo. All participants received 1200 mg calcium carbonate with vitamin D(3) 1000 IU daily. MAIN OUTCOME MEASURES: Bone mineral density (BMD) was measured at baseline and 12 months. Bone turnover was assessed with serum c-terminal telopeptides (CTx) at baseline and 12 months. Tolerability and acceptability were assessed using a validated questionnaire. RESULTS: Mean CTx was suppressed after 12 months for all participants (p=0.04) with no difference in effect size between DHA and control groups (p=0.53). Changes in CTx at 12 months were significantly correlated with changes in BMD at the lumbar spine (p=0.01) and total proximal femur (TPF) (p=0.03). There was a non-significant trend towards rising BMD at 12 months. Participants rated the supplements as tolerable and acceptable, with few adverse events. CONCLUSIONS: The combination of oral calcium, vitamin D(3) and DHA was safe, tolerable and acceptable when used for 12 months by osteopenic individuals in this pilot study. The combination had a positive effect on bone health as indicated by serum CTx, with no effect demonstrated from the addition of DHA 400mg. Changes in BMD at the lumbar spine and TPF were significantly correlated with changes in CTx, which may be useful in monitoring bone health and response to treatment.