People with type 2 diabetes have significantly lower vitamin D levels than those without diabetes, with 74% of diabetic participants showing vitamin D deficiency or insufficiency compared to 44% of non-diabetic participants in a 2026 cross-sectional study of 176 people. According to Gram Research analysis, diabetic participants also had higher levels of chemerin, a protein linked to inflammation and metabolic problems. However, the study shows these factors are associated with metabolic syndrome rather than independently causing it, meaning vitamin D and chemerin may be important markers to monitor but don’t solely determine metabolic health.
A new study from King Abdulaziz University examined how vitamin D levels and a protein called chemerin relate to metabolic syndrome—a cluster of health problems including high blood pressure, excess belly fat, and high blood sugar. Researchers compared 88 people with type 2 diabetes to 88 people without diabetes. They found that people with diabetes had significantly lower vitamin D levels and higher chemerin levels than those without diabetes. While the study shows these factors are connected to metabolic problems, it doesn’t prove that low vitamin D causes these issues. The findings suggest vitamin D and chemerin may be important markers to watch in people managing diabetes.
Key Statistics
A 2026 cross-sectional study of 176 participants found that 74% of people with type 2 diabetes had vitamin D deficiency or insufficiency, compared to only 44% of non-diabetic participants, suggesting vitamin D inadequacy is significantly more common in diabetes.
In the same 2026 study of 176 people, individuals with type 2 diabetes showed significantly higher chemerin levels (a protein associated with inflammation) than non-diabetic comparison participants, indicating elevated inflammatory markers in the diabetic group.
Among 88 diabetic participants in a 2026 study, 20.5% had vitamin D deficiency and 53.4% had insufficient levels, meaning nearly three-quarters of the diabetic group had inadequate vitamin D status.
The Quick Take
- What they studied: How vitamin D levels and a protein called chemerin are connected to metabolic syndrome (a group of health problems) in people with and without type 2 diabetes.
- Who participated: 176 people total: 88 with type 2 diabetes and 88 without diabetes. Each group had equal numbers of men and women (44 of each). The study took place at King Abdulaziz University in Saudi Arabia from August 2021 to December 2022.
- Key finding: People with type 2 diabetes had significantly lower vitamin D levels and higher chemerin levels compared to people without diabetes. About 74% of diabetic participants had vitamin D deficiency or insufficiency, compared to 44% of non-diabetic participants.
- What it means for you: If you have type 2 diabetes, getting your vitamin D levels checked may be worth discussing with your doctor. Low vitamin D appears to be common in people with diabetes, though this study doesn’t prove that vitamin D deficiency causes metabolic problems. This is one piece of information to consider as part of your overall diabetes management.
The Research Details
This was a cross-sectional study, which means researchers took a snapshot in time by measuring vitamin D levels, chemerin levels, and metabolic markers in all participants at one point. They didn’t follow people over time or test whether changing vitamin D levels would improve health outcomes. Participants were divided into two groups: those with type 2 diabetes and those without diabetes. Both groups were matched for gender (equal numbers of men and women). The researchers measured vitamin D using blood tests and classified people as having deficient, insufficient, or sufficient vitamin D based on standard medical guidelines. They also measured chemerin (a protein involved in inflammation) and other markers of metabolic health like blood pressure, waist circumference, blood sugar, and cholesterol levels.
Cross-sectional studies are useful for identifying patterns and associations between different health factors. This approach allowed researchers to compare vitamin D and chemerin levels between diabetic and non-diabetic groups at the same time point. However, because the study was done at one moment in time, it can show that factors are related but cannot prove that one causes the other. This type of study is often a first step that leads to more detailed research to understand cause-and-effect relationships.
The study had a reasonable sample size (176 participants) with balanced groups and equal gender distribution, which strengthens the findings. Blood measurements were done using ELISA, a standard laboratory method. However, the study was conducted at a single location in Saudi Arabia, so results may not apply equally to all populations. The cross-sectional design means we cannot determine whether vitamin D deficiency causes metabolic problems or whether metabolic problems lead to lower vitamin D. The researchers themselves noted that further longitudinal (long-term) and interventional (treatment) studies are needed to understand cause-and-effect.
What the Results Show
People with type 2 diabetes had significantly lower vitamin D levels than people without diabetes. Among the diabetic group, 20.5% had vitamin D deficiency and 53.4% had insufficient levels—meaning nearly three-quarters of diabetic participants had inadequate vitamin D. In comparison, only 8% of non-diabetic participants had deficiency and 36.4% had insufficient levels. The diabetic group also had significantly higher chemerin levels, a protein associated with inflammation and metabolic problems. When researchers looked at metabolic syndrome specifically (the cluster of health problems including high blood pressure, excess belly fat, and abnormal blood sugar and cholesterol), they found that chemerin was higher in people with metabolic syndrome. However, when the researchers used statistical analysis to determine which factors independently predicted metabolic syndrome, only diabetes itself and female sex remained significant—vitamin D and chemerin did not independently predict metabolic syndrome in the adjusted analysis.
The study found that people with metabolic syndrome had higher chemerin levels compared to those without metabolic syndrome. Inflammation markers (measured by CRP) were also elevated in the diabetic group. The research showed that vitamin D insufficiency and deficiency were much more common in people with diabetes than in the non-diabetic comparison group, suggesting vitamin D status may be an important consideration in diabetes management.
Previous research has suggested that vitamin D plays a role in blood sugar control and metabolic health. This study adds to that evidence by showing that people with type 2 diabetes commonly have low vitamin D levels. The finding about chemerin is also consistent with other research showing that this protein is involved in inflammation and metabolic dysfunction. However, this study goes further by showing that while these factors are associated with metabolic problems, they may not be independent predictors of metabolic syndrome when other factors like diabetes status are considered.
This study has several important limitations. First, it was a snapshot in time, so we cannot determine whether low vitamin D causes metabolic problems or whether metabolic problems lead to low vitamin D. Second, the study was conducted at a single location in Saudi Arabia, so the results may not apply to all populations, especially those in different geographic regions with different sun exposure. Third, the study cannot prove cause-and-effect relationships. Fourth, the researchers did not measure vitamin D intake or sun exposure, which affect vitamin D levels. Finally, the study did not follow participants over time to see whether vitamin D supplementation or other interventions would improve metabolic health.
The Bottom Line
If you have type 2 diabetes, discuss vitamin D testing with your healthcare provider. According to Gram Research analysis, this study shows that low vitamin D is common in people with diabetes and may be worth monitoring. However, this research does not yet prove that vitamin D supplementation will improve metabolic health, so any supplementation decisions should be made with your doctor based on your individual vitamin D levels and health status. Moderate confidence: The association between low vitamin D and diabetes is well-established, but this study doesn’t prove supplementation helps.
People with type 2 diabetes should pay attention to these findings, especially if they have metabolic syndrome or multiple metabolic risk factors. Healthcare providers managing diabetes patients may want to consider vitamin D status as part of comprehensive metabolic assessment. People without diabetes may also benefit from maintaining adequate vitamin D levels for overall health, though this study doesn’t specifically address prevention. This research is less relevant for people with well-controlled vitamin D levels or those in regions with abundant sun exposure.
If vitamin D deficiency is identified and supplementation is started, it typically takes 2-3 months to see changes in blood vitamin D levels. Improvements in metabolic markers like blood sugar control may take longer—typically 3-6 months or more. This is not a quick fix but rather part of long-term diabetes management.
Frequently Asked Questions
Does low vitamin D cause type 2 diabetes or metabolic syndrome?
This study shows low vitamin D is associated with diabetes and metabolic problems, but doesn’t prove it causes them. The relationship could work both ways, or other factors could influence both. More long-term research is needed to determine cause-and-effect.
Should I take vitamin D supplements if I have diabetes?
Getting your vitamin D level tested by your doctor is a good first step. If you’re deficient or insufficient, your doctor may recommend supplementation as part of your diabetes management plan. Don’t start supplements without medical guidance.
How common is vitamin D deficiency in people with type 2 diabetes?
This 2026 study found that 74% of diabetic participants had vitamin D deficiency or insufficiency, suggesting it’s very common in people with diabetes. This is significantly higher than the 44% rate in non-diabetic participants.
What is chemerin and why does it matter for diabetes?
Chemerin is a protein involved in inflammation and metabolic regulation. This study found higher chemerin levels in people with diabetes and metabolic syndrome, suggesting it may be a marker of metabolic dysfunction worth monitoring.
Can vitamin D supplementation improve blood sugar control?
This study doesn’t test whether supplementation helps because it only measured vitamin D levels at one point in time. More research is needed to determine if raising vitamin D levels actually improves blood sugar control or metabolic health.
Want to Apply This Research?
- Track your vitamin D levels quarterly (every 3 months) if you have type 2 diabetes. Record the specific blood test result in ng/mL and note whether your doctor classifies it as deficient (<20 ng/mL), insufficient (20-29 ng/mL), or sufficient (≥30 ng/mL). Also track any vitamin D supplementation you take and the dosage.
- If your doctor recommends vitamin D supplementation, set a daily reminder to take it at the same time each day. Log your supplement intake in the app. Additionally, track sun exposure time (15-30 minutes of midday sun several times per week can help with vitamin D production) and note any dietary sources of vitamin D like fatty fish, fortified milk, or egg yolks.
- Create a quarterly review in your app comparing vitamin D levels over time alongside your metabolic markers (blood pressure, waist circumference, fasting blood sugar, triglycerides, and HDL cholesterol). Look for patterns between vitamin D status and your metabolic health. Share this data with your healthcare provider during regular check-ups to inform discussions about diabetes management strategy.
This article summarizes research findings and is not medical advice. Vitamin D status and metabolic syndrome management should be discussed with your healthcare provider, who can order appropriate tests and recommend personalized treatment based on your individual health status, medications, and medical history. Do not start or stop vitamin D supplementation without consulting your doctor. This study shows association, not causation, and individual results may vary based on genetics, geography, diet, and other factors.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.