Worth checking the recently published report from Trinity college dublin called the TILDA study.
The Irish LongituDinal Study on Ageing (TILDA) is a large-scale, nationally representative, longitudinal study on ageing in Ireland, the overarching aim of which is to make Ireland the best place in the world to grow old.
TILDA collects information on all aspects of health, economic and social circumstances from people aged 50 and over in a series of data collection waves once every two years. TILDA is unique amongst longitudinal studies in the breadth of physical, mental health and cognitive measures collected. This data, together with the extensive social and economic data, makes TILDA one of the most comprehensive research studies of its kind both in Europe and internationally.
One finding was that one in eight older adults in Ireland are deficient in vitamin D . Vitamin D food sources are
fatty fish, like tuna, mackerel, and salmon.
Foods fortified with vitamin D, like some dairy products, orange juice, soy milk, and cereals.