TY - JOUR
T1 - Non-skeletal health effects of Vitamin D supplementation
T2 - A systematic review on findings from meta-Analyses summarizing trial data
AU - Rejnmark, Lars
AU - Bislev, Lise Sofie
AU - Cashman, Kevin D.
AU - Eiríksdottir, Gudny
AU - Gaksch, Martin
AU - Grübler, Martin
AU - Grimnes, Guri
AU - Gudnason, Vilmundur
AU - Lips, Paul
AU - Pilz, Stefan
AU - Van Schoor, Natasja M.
AU - Kiely, Mairead
AU - Jorde, Rolf
PY - 2017/7/1
Y1 - 2017/7/1
N2 - 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 randomized clinical trials (RCTs) included in meta-Analyses (MAs) on non-skeletal effects of Vitamin D supplementation. Methods and findings We identified systematic reviews (SR) reporting summary data in terms of MAs of RCTs on selected non-skeletal outcomes. For each outcome, we summarized the results from available SRs and scrutinized included RCTs for a number of predefined characteristics. We identified 54 SRs including data from 210 RCTs. Most MAs as well as the individual RCTs reported null-findings on risk of cardiovascular diseases, type 2 diabetes, weight-loss, and malignant diseases. Beneficial effects of Vitamin D supplementation was reported in 1 of 4 MAs on depression, 2 of 9 MAs on blood pressure, 3 of 7 MAs on respiratory tract infections, and 8 of 12 MAs on mortality. Most RCTs have primarily been performed to determine skeletal outcomes, whereas non-skeletal effects have been assessed as secondary outcomes. Only one-Third of the RCTs had low level of 25OHD as a criterion for inclusion and a mean baseline 25OHD level below 50 nmol/L was only present in less than half of the analyses . Conclusions Published RCTs have mostly been performed in populations without low 25OHD levels. 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.
AB - 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 randomized clinical trials (RCTs) included in meta-Analyses (MAs) on non-skeletal effects of Vitamin D supplementation. Methods and findings We identified systematic reviews (SR) reporting summary data in terms of MAs of RCTs on selected non-skeletal outcomes. For each outcome, we summarized the results from available SRs and scrutinized included RCTs for a number of predefined characteristics. We identified 54 SRs including data from 210 RCTs. Most MAs as well as the individual RCTs reported null-findings on risk of cardiovascular diseases, type 2 diabetes, weight-loss, and malignant diseases. Beneficial effects of Vitamin D supplementation was reported in 1 of 4 MAs on depression, 2 of 9 MAs on blood pressure, 3 of 7 MAs on respiratory tract infections, and 8 of 12 MAs on mortality. Most RCTs have primarily been performed to determine skeletal outcomes, whereas non-skeletal effects have been assessed as secondary outcomes. Only one-Third of the RCTs had low level of 25OHD as a criterion for inclusion and a mean baseline 25OHD level below 50 nmol/L was only present in less than half of the analyses . Conclusions Published RCTs have mostly been performed in populations without low 25OHD levels. 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.
UR - http://www.scopus.com/inward/record.url?scp=85022336357&partnerID=8YFLogxK
U2 - https://doi.org/10.1371/journal.pone.0180512
DO - https://doi.org/10.1371/journal.pone.0180512
M3 - Review article
C2 - 28686645
SN - 1932-6203
VL - 12
JO - PLOS ONE
JF - PLOS ONE
IS - 7
M1 - e0180512
ER -