The Relationship between Vitamin D and Type 2 Diabetes Is Intriguing: Glimpses from the Spect-China Study

Abstract

Objective: Vitamin D is a multifunctional vitamin for our body. Type 2 diabetes mellitus (T2DM) is a common metabolic disease. Whether T2DM affects the serum 25(OH)D level has not been reported. The objective of this study was to reveal the extent to which vitamin D is present in the population in East China and to explore the relationship between serum 25(OH)D and T2DM. Methods: The cohort was selected based on a large investigation named Survey on Prevalence in East China including 12,702 participants aged 21-92 years old. All the participants completed the questionnaire and went through a physical examination. Fasting blood samples were collected to test serum 25(OH)D and other metabolism-related indicators. AVONA was used to test the significance of differences among groups. Multinomial logistic regression was used to assess the association of T2DM with serum 25(OH)D level. Results: The overall percentage of vitamin D deficiency was 80.55% (male 74.1%, female 85.0%). Men with lower serum 25(OH)D level had high value in homeostasis model assessment of insulin resistance and HbA1c. The serum 25(OH)D level of those who were diagnosed with T2DM was higher than that in non-diabetics. The serum 25(OH)D level of pre-diabetes was the highest. T2DM patients trended to have higher serum 25(OH)D levels. Conclusion: Vitamin D deficiency is common among the people in East-China. T2DM patients had higher levels of serum 25(OH)D. The relationship between vitamin D and T2DM is intriguing. It seemed that vitamin D was either irrelevant directly to T2DM or resisted in T2DM patients.

Serum 25-hydroxyvitamin D, genetic susceptibility, and the risk of incident type 2 diabetes: A prospective cohort in East China

“…When vitamin D is insufficient in the body to meet skeletal metabolism and nonskeletal functions, such as acting on VDR in β-cells, circulating 25(OH)D may compensatorily increase but fail to reach the ideal level, which may lead to a different relationship between 25(OH)D and incident T2DM. [6] To explain why our results differ from other studies, a new mechanism merits further investigation to expand previous theories, and well-designed experiments are necessary.…”

“…[5] In East China, 80.55% of adults have serum 25(OH)D <50 nmol/L, which is higher than that in Europe (45.6%-56.0%) according to four nationally representative surveys. [6] Previous studies provided evidence that vitamin D deficiency could impair b-cell function, cause insulin resistance, and thereby be associated with an increased risk of T2DM. [7,8] However, this conclusion is still inconsistent and varies within populations.…”

Sex-Specific Association between Serum 25-Hydroxyvitamin D and Metabolic Risk Factors in T2DM Patients

“…However, there are limited studies evaluating the relationship between 25(OH)D concentrations and metabolic risk factors in Chinese populations [8][9][10][11][12][13][14], especially in T2DM patients [12][13][14]. Lu et al [8] linked this relationship to glucose control in their study of individuals in East China. However, sex-specific differences have not been explored, although several studies indicate that the association between 25(OH)D levels and metabolic risk was stronger in men than women [9,10].…”