Glucose Metabolism Effects of Vitamin D Supplementation in Prediabetes

Summary

Vitamin D deficiency is widespread throughout the world, and the deficiency has been associated with several chronic diseases, such as cardiovascular diseases and diabetes. In Nordic countries, like in Finland, there is a particular variation in vitamin D status, and during wintertime, when there is no exposure to ultraviolet-B light from the sun, serum concentrations of vitamin D decrease substantially. In Finland, some 40% of middle-aged men and one third of women also have some degree of impairment of glucose metabolism.

The purpose of this trial is to investigate the effects of two different daily doses of vitamin D on glucose metabolism in men 60 years of age or older and who are vitamin D deficient, have a high body mass index and at least two characteristics of cardio-metabolic syndrome.

Altogether 102 subjects with low serum calcidiol (\<60 nmol/L) will be recruited and randomized to one of the three groups: 1) 40 µg/d vitamin D3, 2) 80 µg/d vitamin D3 or 3) placebo. The supplementation period will last for 6 months from September 2011 to March 2012.

The main hypotheses of the trial are: (1.) Vitamin D supplementation will improve glucose and insulin metabolism in people with a low baseline vitamin D status, in a dose-dependent manner. (2.) Vitamin D supplementation will have an effect on the expression of genes involved in glucose and insulin metabolism and inflammation. (3.) Vitamin D supplementation will have an effect on epigenetic changes in key genes participating in vitamin D metabolism.

Conditions

• Prediabetic State
• Overweight
• Obese

Interventions

DIETARY_SUPPLEMENT

Vitamin D3

Vitamin D3 40 micrograms (1600 IU) per day

DIETARY_SUPPLEMENT

Placebo

Inactive placebo

DIETARY_SUPPLEMENT

Vitamin D 80

Vitamin D3 80 micrograms (3200 IU) per day

Sponsors & Collaborators

• Academy of Finland

  collaborator OTHER

• Juho Vainio Foundation

  collaborator OTHER

• Finnish Foundation for Cardiovascular Research

  collaborator OTHER

• Diabetes Research Foundation, Finland

  collaborator OTHER

• University of Eastern Finland

  lead OTHER

Principal Investigators

• Tomi-Pekka Tuomainen, MD, PhD · University of Eastern Finland

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-09-30

Primary Completion

2012-05-31

Completion

2012-05-31

Countries

• Finland

Study Locations