MEDICAL RESEARCH: Vitamin D Deficiency is Associated with Insulin Resistance and ß cell Dysfunction

Editor’s note:

In the following medical research study, healthy participants were enrolled to examine the effects of vitamin D on insulin production and use in the body. This research shows that:

1) Vitamin D plays an important role in insulin sensitivity in the body, and deficiency of vitamin D hampers production of insulin hormone by beta cells in the pancreas.

2) People with vitamin D deficiency are at risk for developing type 2 diabetes mellitus. Type 2 diabetes mellitus is characterized by lack of insulin sensitivity in body tissues and inadequate production of insulin hormone in the pancreas.

 *  “25-hydroxyvitamin D [25(OH)D] “is the activated
form of vitamin D in the body.

*  “ß cells” are the insulin producing cells of the pancreas.

 “Hypovitaminosis D is is Associated with Insulin Resistance and ß cell Dysfunction”

Researchers: Ken C Chiu, Audrey Chu, Vay Liang W Go and Mohammed F Saad

1 From the Division of Clinical Epidemiology and Preventive Medicine and the Center for Clinical Nutrition, Department of Medicine, University of California, Los Angeles, School of Medicine, Los Angeles.

Background: Although the role of vitamin D in type 2 diabetes is well recognized, its relation to glucose metabolism is not well studied.

Objective: We investigated the relation of 25-hydroxyvitamin D [25(OH)D] concentrations to insulin sensitivity and ß cell function.

Design: We enrolled 126 healthy, glucose-tolerant subjects living in California. Insulin sensitivity index (ISI) and first- and second-phase insulin responses (1stIR and 2ndIR) were assessed by using a hyperglycemic clamp.

Results: Univariate regression analyses showed that 25(OH)D concentration was positively correlated with ISI and negatively correlated with 1stIR and 2ndIR.

Multiple regression analyses confirmed an independent correlation between 25(OH)D concentration and ISI. No independent correlation was observed between 25(OH)D concentration and 1stIR or 2ndIR. However, an independent negative relation of 25(OH)D concentration with plasma glucose concentration was observed at fasting, 60 min, 90 min, and 120 min during the oral-glucose-tolerance test.

Subjects with hypovitaminosis D (<20 ng/mL) had a greater prevalence of components of metabolic syndrome than did subjects without hypovitaminosis D (30% compared with 11%).

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Author Information: Cleo Libonati, RN, BSN
Cleo Libonati is president/CEO and co-Founder of Gluten Free Works, Inc. She is the author of Recognizing Celiac Disease.
She can be reached by E-mail.