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Effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes: a systematic review of interventional studies.

Nigil Haroon N, Anton A, John J, Mittal M - J Diabetes Metab Disord (2015)

Bottom Line: Diabetes and vitamin D deficiency are global epidemics.However, the evidence was weak due to the low methodological quality of the studies.There was no significant effect on HbA1c, beta cell function and insulin resistance in the long-term studies (follow up > 3 months).

View Article: PubMed Central - PubMed

Affiliation: Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, ON Canada.

ABSTRACT

Background: Diabetes and vitamin D deficiency are global epidemics. Researchers have long been exploring the role of potentially modifiable factors to manage type 2 diabetes. We conducted a systematic review of prospective studies and randomized controlled trials that involved vitamin D supplementation and specifically intended to study glycemic outcomes related to type 2 diabetes.

Methods: Two authors independently searched Medline and PubMed for longitudinal studies that had assessed the effect of vitamin D supplements on glycemic control, insulin resistance and beta-cell dysfunction in patients with diabetes.

Results: Seventeen randomized control trials and seven longitudinal studies with a minimum follow-up of one month were included. Results of the various short-term studies (follow up ≤ 3 months) suggested that vitamin D supplementation had a positive impact on glycemic control and metabolic parameters such as insulin resistance and beta cell dysfunction. However, the evidence was weak due to the low methodological quality of the studies. There was no significant effect on HbA1c, beta cell function and insulin resistance in the long-term studies (follow up > 3 months). There existed heterogeneity in the methodology of the studies, inclusion criteria, mode of supplementation of vitamin D and the duration of follow up.

Conclusions: Current evidence based on randomized controlled trials and longitudinal studies do not support the notion that vitamin D supplementation can improve hyperglycemia, beta cell secretion or insulin sensitivity in patients with type 2 diabetes. Large-scale trials with proper study design, optimal vitamin D supplementation and longer follow up need to be conducted.

No MeSH data available.


Related in: MedlinePlus

Flow chart for identifying eligible studies.
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Related In: Results  -  Collection

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Fig1: Flow chart for identifying eligible studies.

Mentions: Two authors conducted the literature search independently. Systematic searches of MEDLINE and EMBASE were conducted from inception to July 31, 2014. The main aim was to identify randomized controlled trials that assessed the effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes. The search strategy is outlined in Figure 1.Figure 1


Effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes: a systematic review of interventional studies.

Nigil Haroon N, Anton A, John J, Mittal M - J Diabetes Metab Disord (2015)

Flow chart for identifying eligible studies.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4340830&req=5

Fig1: Flow chart for identifying eligible studies.
Mentions: Two authors conducted the literature search independently. Systematic searches of MEDLINE and EMBASE were conducted from inception to July 31, 2014. The main aim was to identify randomized controlled trials that assessed the effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes. The search strategy is outlined in Figure 1.Figure 1

Bottom Line: Diabetes and vitamin D deficiency are global epidemics.However, the evidence was weak due to the low methodological quality of the studies.There was no significant effect on HbA1c, beta cell function and insulin resistance in the long-term studies (follow up > 3 months).

View Article: PubMed Central - PubMed

Affiliation: Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, ON Canada.

ABSTRACT

Background: Diabetes and vitamin D deficiency are global epidemics. Researchers have long been exploring the role of potentially modifiable factors to manage type 2 diabetes. We conducted a systematic review of prospective studies and randomized controlled trials that involved vitamin D supplementation and specifically intended to study glycemic outcomes related to type 2 diabetes.

Methods: Two authors independently searched Medline and PubMed for longitudinal studies that had assessed the effect of vitamin D supplements on glycemic control, insulin resistance and beta-cell dysfunction in patients with diabetes.

Results: Seventeen randomized control trials and seven longitudinal studies with a minimum follow-up of one month were included. Results of the various short-term studies (follow up ≤ 3 months) suggested that vitamin D supplementation had a positive impact on glycemic control and metabolic parameters such as insulin resistance and beta cell dysfunction. However, the evidence was weak due to the low methodological quality of the studies. There was no significant effect on HbA1c, beta cell function and insulin resistance in the long-term studies (follow up > 3 months). There existed heterogeneity in the methodology of the studies, inclusion criteria, mode of supplementation of vitamin D and the duration of follow up.

Conclusions: Current evidence based on randomized controlled trials and longitudinal studies do not support the notion that vitamin D supplementation can improve hyperglycemia, beta cell secretion or insulin sensitivity in patients with type 2 diabetes. Large-scale trials with proper study design, optimal vitamin D supplementation and longer follow up need to be conducted.

No MeSH data available.


Related in: MedlinePlus