Can Vitamin D Help Reverse Prediabetes? Here’s What the Latest Research Says

Posted by The Functional Journal Team
*Exploring the science behind supplements and metabolic health*

The Big Question:

Can a daily dose of vitamin D actually help reverse prediabetes — not just slow its roll?

According to a brand-new 2025 meta-analysis, the answer is: yes — with some caveats.

Researchers pulled together data from 10 high-quality clinical trials (4,478 participants) and found that people supplementing with vitamin D were 27% more likely to return to normal glucose regulation (NGR) than those who didn’t.

🧬 Key Stat: 44 more people per 1,000 reversed their prediabetes with vitamin D compared to placebo.

Why This Matters

Prediabetes affects over 1 in 3 adults in the U.S. and is often a precursor to type 2 diabetes, heart disease, and more.

In functional medicine, we believe in identifying and reversing imbalances early — before they spiral.

This study supports the idea that vitamin D could be a key player in that reversal, especially when combined with lifestyle interventions like movement, sleep, protein intake, and stress reduction.

Here’s What Makes This Study Credible

• 🧪 Gold-standard methods (PRISMA, GRADE, PROSPERO-registered)
• ✅ Low risk of bias
• 📈 Consistent results across different definitions and trial durations
• ⚖️ No major side effects — hypercalcemia was rare and not statistically significant.

So Should You Supplement?

If you or someone you love is dealing with prediabetes:

• Ask your provider to check 25(OH)D levels.
• Work with a practitioner to safely supplement — most studies used between 2,000–4,000 IU/day.
• Pair it with real lifestyle shifts — vitamin D is a support, not a substitute.

Final Takeaway

“Vitamin D is low-risk, affordable, and backed by real science — not just influencer hype. In the functional medicine toolkit, it’s a quiet hero for blood sugar balance.”