Diabetes not prevented or treated if give only modest amount of vitamin D or for short period of time – meta-analysis July 2014

Effect of Vitamin D3 Supplementation on Improving Glucose Homeostasis and Preventing Diabetes: A Systematic Review and Meta-Analysis

The Journal of Clinical Endocrinology & Metabolism DOI: http://dx.doi.org/10.1210/jc.2014-2136
Jennifer C. Seida MPH1, Joanna Mitri MD2, Isabelle N. Colmers MSc1, Sumit R. Majumdar MD1,3, Mayer B. Davidson MD4, Alun L. Edwards MD5, David A. Hanley MD5, Anastassios G. Pittas MD2, Lisa Tjosvold MLIS1, and Jeffrey A. Johnson PhD1
1Alliance for Canadian Health Outcomes Research in Diabetes, University of Alberta, Edmonton;
2Tufts Medical Center, Boston;
3Division of General Internal Medicine, Department of Medicine, University of Alberta, Edmonton;
4Charles R Drew University, Los Angeles;
5University of Calgary, Calgary

Context:
Observational studies report consistent associations between low vitamin D concentration and increased glycemia and risk of type 2 diabetes, but results of randomized controlled trials (RCTs) are mixed.
Objective:
To systematically review RCTs that report on the effects of vitamin D supplementation on glucose homeostasis or diabetes prevention.
Data Sources:
MEDLINE, EMBASE, SCOPUS, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and Science Citation Index from inception to June 2013.
Study Selection:
Trials that compared vitamin D3 supplementation with placebo or a non-vitamin D supplement in adults with normal glucose tolerance, prediabetes, or type 2 diabetes.
Data Extraction and Synthesis:
Two reviewers collected data and assessed trial quality using the Cochrane Risk of Bias tool. Random effects models were used to estimate mean differences (MD) and odds ratios (OR). The main outcomes of interest were HOMA–IR, HOMA–B, hemoglobin A1c levels, fasting blood glucose, incident diabetes, and adverse events.
Data Synthesis:
Thirty-five trials (43,407 patients) with variable risk of bias were included. Vitamin D had no significant effects on insulin resistance (HOMA–IR: MD, -0.04; 95%CI, -0.30 to 0.22, I2=45%), insulin secretion (HOMA–B: MD, 1.64; 95%CI, -25.94 to 29.22, I2=40%), or A1c (MD, -0.05%; 95%CI, -0.12 to 0.03, I2=55%) compared with controls. Four RCTs reported on progression to new diabetes and found no effect of vitamin D (OR, 1.02; 95%CI, 0.94 to 1.10, I2=0%). Adverse events were rare, and there was no evidence of publication bias.
Conclusions:
Evidence from available trials shows no effect of vitamin D3 supplementation on glucose homeostasis or diabetes prevention. Definitive conclusions may be limited in the context of the moderate degree of heterogeneity, variable risk of bias, and short-term follow-up duration of the available evidence to date.

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PDF is attached at the bottom of this page

Only noticed 3 studies which lasted long enough (> 4 months) which also used enough vitamin D (>4,000 IU) for the average adult
Unfortunately, they were for studies of OBESE adults - who need 8,000 - 12,000 IU

See also VitaminDWiki

Overview Diabetes and vitamin D contains the following summary

• Diabetes is 5X more frequent far from the equator
• Children getting 2,000 IU of vitamin D are 8X less likely to get Type 1 diabetes
• Obese people get less sun / Vitamin D - and also vitamin D gets lost in fat
• Sedentary people get less sun / Vitamin D
• Worldwide Diabetes increase has been concurrent with vitamin D decrease and air conditioning
• Elderly get 4X less vitamin D from the same amount of sun
      Elderly also spend less time outdoors and have more clothes on
• All items in category Diabetes and Vitamin D 562 items: both Type 1 and Type 2

Vitamin D appears to both prevent and treat diabetes

• Appears that >2,000 IU will Prevent
• Appears that >4,000 IU will Treat , but not cure
• 90% less T2 Diabetes in the group having lots of Vitamin D
• Appears that Magnesium helps both Prevention and Treatment
• Many diabetics would be better treated if Gut-Friendly Vitamin D were used

Number of articles in both categories of Diabetes and:

• Dark Skin 25;   Intervention 57;   Meta-analysis 40;   Obesity 37;  Pregnancy 45;   T1 (child) 39;  Omega-3 12;  Vitamin D Receptor 25;  Genetics 13;  Magnesium 32    Click here to see details

Some Diabetes studies

• Take Vitamin D to prevent prediabetes from progressing into diabetes – American Diabetic Association – 2024
• Diabetes and Vitamin D meta-analyses - many studies 39+ as of Nov 2024
• 99.7% of people who got Diabetes had been regularly consuming food emulsifiers - May 2024
• Type 2 Diabetes treated by Vitamin D (often 50,000 IU weekly) – meta-analysis July 2023
• Diabetic inflammation synergistically decreased by Vitamin D and exercise – RCT June 2022
• Incidence of Type-2 Diabetes increased 3X in 30 years (by the way, Vitamin D helps) – July 2022
• Vitamin d treats Type II Diabetes in many ways (14 article review) - Sept 2021
• T2 Diabetes 30 percent more likely if poor Vitamin D Receptor – meta-analysis of 47 studies – July 2021

50 ng of Vitamin D fights Diabetes

• Saudi study defines normal Vitamin D level to be 50 to 70 ng (diabetes, etc.) - June 2020
• Diabetes 5X less likely if more than 50 ng of Vitamin D – April 2018

T1 Diabetes

• T1 Diabetes 3X lower risk if high vitamin D (over 40 ng) – Meta-analysis Nov 2020
• Type 1 Diabetes is prevented and treated by Vitamin D – review of 16 studies – Sept 2019
• Type 1 Diabetes prevention with Vitamin D and Omega-3 – Symposium April 2019

Pre-Diabetes

• 4X reduction in prediabetes progressing to T2D if more than 50 ng of vitamin D – RCT March 2023
• Prediabetes reduced by weekly 60,000 IU of Vitamin D – RCT Jan 2021
• Prediabetes 1.5 X more likely to go away if take Vitamin D – meta-analysis July 2020

Diabetes, Metabolic Syndrome and Magnesium - many studies

Pages listed in BOTH the categories Diabetes and Meta-analysis