Vitamin D Deficiency, Insulin Resistance and FGF-23

• Status: Completed
• Trial end date: 0000-00-00
• Target enrollment: 90
• Participant gender: Both

Summary

The purpose of this project is to determine if treating vitamin D deficiency decreases insulin resistance and improves insulin secretion in healthy volunteers. Additionally, this project will investigate if treating vitamin D deficiency affects a new phosphate-regulating hormone called FGF-23.

• Phase: N/A
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Massachusetts General Hospital
• Treatments: Ergocalciferols; Insulin; Vitamin D; Vitamins
• Last Updated: 2008-03-26

Criteria

Inclusion Criteria:

• Age 18 to 45 yrs

• Serum 25-OHD < or = 20 ng/mL

• At least 1 menses in the last 3 months (females) and normal serum testosterone (males)

Exclusion Criteria:

• Significant cardiac, hepatic, oncologic, or psychiatric disease

• History of diabetes mellitus, malabsorption, kidney stones, or recent alcohol excess/abuse (15 drinks per week in the last month)

• Fasting glucose > 126 mg/dl or 2 hour OGTT > 200 mg/dl

• Use of medications known to affect serum phosphate levels including phosphate-binding antacids, sodium etidronate, calcitonin, excessive doses of vitamin D (> 1000 units per day), excessive doses of vitamin A (> 20,000 units/day), calcitriol, growth hormone, or anti-convulsants

• Use of metformin or insulin sensitizing agents

• Serum calcium < 8 or > 11 mg/dL, creatinine > 1.5 mg/dL, or Hgb < 11 gm/dL

• Liver function tests > 2 times the upper limit of normal

• TSH < 0.1 or > 7 uU/mL

• WBC < 2,000 or > 15,000/cmm

• Platelet count < 100,000 or > 500,000/cum

• Hormone replacement therapy or testosterone use

• Urine uhCG positive (females), testosterone < 270 ng/dL (males)