The fact that most MAs on results from RCTs did not show a beneficial effect does not disprove the hypothesis suggested by observational findings on adverse health outcomes of low 25OHD levels
Background A large number of observational studies have reported harmful effects of low 25-hydroxyvitamin D ( 25OHD ) levels on non-skeletal outcomes .
We performed a systematic quantitative review on characteristics of r and omized clinical trials ( RCTs ) included in meta-analyses ( MAs ) on non-skeletal effects of vitamin D supplementation .
Vitamin D supplementation and the prevention of fractures and falls: results of a randomised trial in elderly people in residential accommodation.
OBJECTIVES To determine whether vitamin D supplementation reduces the risk of fracture or falls in elderly people in care home accommodation . DESIGN A r and omised controlled trial of cluster design . SETTING AND SUBJECTS 223 Residential units ( mainly identical 30-bedded units ) , within 118 homes for elderly people throughout Britain , with 3,717 participating residents ( 76 % women , average age 85 years ) . The units provided mainly or entirely residential care ( 35 % of residents ) , nursing care ( 42 % ) or care for elderly mentally infirm ( EMI ) residents ( 23 % ) . METHODS Participants were r and omly allocated by residential unit ( cluster design ) to a treated group offered ergocalciferol 2.5 mg every 3 months ( equivalent to a daily dose of 1,100 IU ) , or to a control group .  Fractures were reported by staff and confirmed in hospital , and routinely collected data on reported falls were obtained . RESULTS After median follow-up of 10 months ( interquartile range 7 - 14 months ) , 64 ( 3.6 % ) of 1,762 vitamin D-treated residents and 51 ( 2.6 % ) of 1,955 controls had one or more non-vertebral fractures , and 24 ( 1.3 % ) and 20 ( 1.0 % ) , respectively , had a hip fracture . The proportion reporting at least one fall was 44 % in vitamin D-treated and 43 % in control residents . The differences between the vitamin D and control groups were not statistically significant . The incidence of all non-vertebral fractures in the care homes ( 3.2 % per year ) and of hip fractures ( 1.1 % per year ) was low , similar to rates in elderly people in sheltered accommodation , and the pre-treatment serum 25-hydroxy vitamin D concentration was high [ median 47 nmol/l , measured in a 1 % ( n = 18 ) sample ] . CONCLUSIONS We found no evidence that vitamin D prevents fractures or falls in elderly people in care home accommodation
The fact that most MAs on results from RCTs did not show a beneficial effect does not disprove the hypothesis suggested by observational findings on adverse health outcomes of low 25OHD levels
Background A large number of observational studies have reported harmful effects of low 25-hydroxyvitamin D ( 25OHD ) levels on non-skeletal outcomes .
We performed a systematic quantitative review on characteristics of r and omized clinical trials ( RCTs ) included in meta-analyses ( MAs ) on non-skeletal effects of vitamin D supplementation .