Vitamin D and Prediabetes: Treat-To-Target Study (D2dTTT)

Could Vitamin D Help Improve Glucose Levels in People with Prediabetes?

Researchers at Tufts Medical Center are conducting a new clinical study to learn whether a personalized vitamin D treatment strategy can improve blood sugar health in adults with prediabetes who are at high risk of developing type 2 diabetes.

Previous research, including the original D2d Study, suggested that vitamin D may modestly lower diabetes risk in some adults with prediabetes. This new study takes the next step by testing a treat-to-target approach—adjusting the vitamin D dose to reach blood levels that may be most effective.

Who May Qualify?

You may be eligible if you:

  • Are 30 to 74 years old
  • Have prediabetes (hemoglobin A1c between 5.7 and 6.4% and fasting blood glucose between 100 and 125 mg/dL)
  • Have a BMI between 23 and 35
  • Are willing to participate for approximately 18 months
  • Are willing to wear a continuous glucose monitor (CGM) during study periods

What Does Participation Involve?

Participants will be followed for 18 months and may receive either:

  • Vitamin D solution by mouth weekly with dose adjusted during the study, or
  • Placebo solution by mouth weekly
  • Study visits at Tufts Medical Center in downtown Boston
  • Blood tests
  • Questionnaires
  • Continuous glucose monitor monitoring

Interested? Contact Us

To learn more or see if you may qualify:

Division of Endocrinology Research Team
Tufts Medical Center: endocrine-research@tuftsmedicine.org | 617‑636‑3232

Interested? Contact Us

To learn more or see if you may qualify:

Division of Endocrinology Research Team
Tufts Medical Center:
endocrine-research@tuftsmedicine.org
617‑636‑3232