Reduced bone mineral density, altered calcium homeostasis (regulation and equilibrium of calcium levels and function) and increased risk of hip fracture are all seen after a stroke. A deficiency of vitamin D is well documented in long-term stroke survivors. In this study the levels of vitamin D were checked in patients who suffered a first acute stroke (acute means sudden and severe).

The Physicians Health Study involved 22,071 male doctors in the USA, 68% of whom supplied blood samples at the start of the study in 1982. A total of 15,000 did not have cardiovascular disease at the start of the study, and 297 of these developed an ischemic stroke during the studies 13 year follow up. It was found that having low levels of Alpha-Carotene, Beta-Carotene, and Lycopene increased the risk of ischemic stroke by 40%.