Vitamin D and Type 2 Diabetes - Treat-To-Target

Summary

This study tests whether taking a weekly dose of vitamin D, with the dose adjusted to reach a target blood vitamin D level, can help control blood sugar levels in adults at high risk of developing type 2 diabetes (prediabetes). Research suggests that vitamin D may play a role in blood sugar control. The goal of this study is to see whether adjusting the dose of vitamin D to reach a specific blood vitamin D level improves blood sugar control compared with a placebo (a look-alike pill without vitamin D). One hundred adults aged 30 to 74 with prediabetes will take part. Participants will be randomly assigned (by chance) to receive either weekly vitamin D supplements or a placebo. Neither the participants nor the research team will know which group a participant is in during the study. Participants in the vitamin D group will start with one specific dose. After three months, a blood test will be used to decide whether the dose should stay the same or be increased to reach the target vitamin D level. Participants in the placebo group will continue taking the placebo each week. All participants will be followed for about 18 months. During the study, they will attend scheduled study visits, have blood tests, and wear a continuous glucose monitor, a small device that measures blood sugar levels throughout the day and night. The research team will also make periodic phone calls to check on health changes, medication use, and study participation. The main outcome of the study is the proportion of time that the participants' blood sugar levels remains in a healthy range.

Timeline

Start

2026-05

Primary completion

2030-03

Completion

2031-03

Publications

• Background Chatterjee R, Davenport CA, Vickery EM, Johnson KC, Kashyap SR, LeBlanc ES, Nelson J, Dagogo-Jack S, Pittas AG, Hughes BD; D2d Research Group. Effect of intratrial mean 25(OH)D concentration on diabetes risk, by race and weight: an ancillary analysis in the D2d study. Am J Clin Nutr. 2023 Jul;118(1):59-67. doi: 10.1016/j.ajcnut.2023.03.021. Epub 2023 Mar 29.
• Background Pittas AG, Kawahara T, Jorde R, Dawson-Hughes B, Vickery EM, Angellotti E, Nelson J, Trikalinos TA, Balk EM. Vitamin D and Risk for Type 2 Diabetes in People With Prediabetes : A Systematic Review and Meta-analysis of Individual Participant Data From 3 Randomized Clinical Trials. Ann Intern Med. 2023 Mar;176(3):355-363. doi: 10.7326/M22-3018. Epub 2023 Feb 7.
• Background Pittas AG, Dawson-Hughes B, Sheehan P, Ware JH, Knowler WC, Aroda VR, Brodsky I, Ceglia L, Chadha C, Chatterjee R, Desouza C, Dolor R, Foreyt J, Fuss P, Ghazi A, Hsia DS, Johnson KC, Kashyap SR, Kim S, LeBlanc ES, Lewis MR, Liao E, Neff LM, Nelson J, O'Neil P, Park J, Peters A, Phillips LS, Pratley R, Raskin P, Rasouli N, Robbins D, Rosen C, Vickery EM, Staten M; D2d Research Group. Vitamin D Supplementation and Prevention of Type 2 Diabetes. N Engl J Med. 2019 Aug 8;381(6):520-530. doi: 10.1056/NEJMoa1900906. Epub 2019 Jun 7.

Drugs

Indications