Our son has been living with Type 1 Diabetes for the past 3.5 years. During our research, we came across studies suggesting a possible link between Vitamin D deficiency and T1D. With the goal of preserving his remaining beta cells and supporting his immune system (as his Vitamin D levels were low), we started supplementing with 5000 IU Vitamin D capsules.
Over time, we’ve noticed significant improvements in his overall blood glucose control, consistently maintaining an HbA1c in the 6.2–6.7% range. Along with careful weight and carbohydrate tracking, he’s able to enjoy most foods and even participates in occasional parties.
We wanted to share our experience in case others might benefit from considering Vitamin D supplementation. One thing to be aware of: improved insulin sensitivity from Vitamin D may increase the risk of nighttime hypoglycemia, so it’s important to monitor closely.
Hello @rsesma Vitamin D deficiency is quite common to type 1 but Vitamin D cannot control blood sugar. I get blood tests annually one test is for vitamin D and I take a supplement when I get to low-normal. It is always recommended to talk to a doctor because this vitamin is stored in body fat and you don’t want too much.
I have been living with T2D for about 7 years and only recently started taking a vitamin D3 supplement after testing revealed I was severely deficient. My most recent test results showed my vitamin D levels had nearly doubled, but my A1c has gone up slightly during that time.
I have always been very careful about maintaining tight control of my blood sugar with my prescribed medications including metformin, SGLT-2 inhibitors, insulin, and GLP-1s since my diagnosis in adulthood. The most significant change I made recently was starting to take the vitamin D supplement, though I acknowledge other factors could also influence A1c levels. I am wondering if there is any research or shared experiences regarding whether vitamin D supplements might affect A1c results, or if others have observed similar patterns with their glucose management.
@MarcusOC My Vitamin D tested low so I started a supplement and my level doubled also. Still wasn’t over the threshold of 30-something so my doc increased the dose, I got tested again and after a couple of rounds of that process my Vitamin D is finally in the 30’s. Now my doc and I are working on why it was so hard to raise the level.
The other thing to keep in mind is the A1C is an “estimate” according to Gary Scheiner in Think Like A Pancreas. Personally I think the A1C is a sledge hammer of a test. Results from different labs using different test methodologies can result in +/- .5 difference. The fingerstick versions are less accurate. There are things that can interfere like anemia. This paper has a list. [ Methods, units and quality requirements for the analysis of haemoglobin A1c… - PMC](Methods, units and quality requirements for the analysis of haemoglobin A1c in diabetes mellitus - PMC) Since you’re a T2D using insulin you’ve got a CGM right? Has your time in range increased or your standard deviation decreased? Again, it doesn’t have to but it’d be nice if fixing one problem didn’t just uncover another problem.
It looks like my last Vitamin D test was May of 2024 (just a few months after diagnosis) and it was 72. I don’t know if Vitamin D results are “embedded” in other tests they get but since I haven’t seen any since I’ll ask my doctor if i should have them checked again.
Thank you! I had heard of that dose as a treatment option and wondered how well it worked. I know every body is different but for what it’s worth all my immediate family members are Vitamin D deficient. Might be worth talking to yours about it.