Importance of Dosing Regimen for the Effect of Vitamin D Supplementation

• Status: Completed
• Trial end date: 2018-05-01
• Target enrollment: 0
• Participant gender: All

Summary

Vitamin D is a hormone with effects not only on the skeleton, but on most tissues in the body. Lack of vitamin D is associated with cardio-vascular disease (CVD), type 2 diabetes, cancer, infectious and immunological diseases, as well as risk factors for these diseases. However, intervention studies with vitamin D have been inconclusive regarding diseases and risk factors. This could be due to inclusion of subjects already vitamin D sufficient, and short and underpowered studies. In addition, there are indications that the dosing regimens may be important, so that daily doses with vitamin D are more efficient than intermittent doses, which so far have been generally used. This could be related to the concentration of circulating and thereby intracellular vitamin D concentrations, which probably is dependent on daily vitamin D doses. This will be tested in the present study where 60 subjects will be randomized to vitamin D 160 000 once, vitamin D 4000 IU/day, or placebo for four weeks. The primary endpoints will be effects on serum hepcidin and plasma cathelicidin after 4 weeks, with effects on serum PTH, RNA expression and microRNA in peripheral blood, telomerase activity in peripheral blood mononuclear cells and the ration between serum 1,25(OH)2D and 24,25(OH)2D as secondary endpoints.

• Phase: Phase 3
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: University of Tromso
• Treatments: Ergocalciferols; Vitamin D; Vitamins

Criteria

Inclusion Criteria:- Males and females 20 - 70 years

• 20 kg/m2 > BMI < 35 kg/m2

• systolic BP < 175 mmHg, diastolic BP < 105 mmHg

• Serum 25(OH)D level < 50 nmol/L. Serum 25(OH)D < 50 nmol/L is considered as vitamin D deficiency, and accordingly, effects of vitamin D supplementation will be easier to detect than if the included subjects were vitamin D sufficient.

• Hgb, SR, CRP, creatinine < 130 umol/L in males, < 120 umol/L in females, calcium, FT4 and TSH within the normal reference range; ASAT < 90 mU/L ALAT < 140 U/L, HbA1c < 6.6 %

• The subjects must agree not to take any vitamin D supplementation, including cod liver oil or "mølje", use solarium or go on sunny vacation during the intervention period.

Exclusion Criteria:

• subjects allergic to peanuts

• subjects with primary hyperparathyroidism

• granulomatous diseases (sarcoidosis, tuberculosis, Wegner's granulomatosis)

• diabetes

• renal stones the last five years

• subjects seriously ill (or with chronic disease) and unfit for participation in the study (as judged by one of the study doctors)

• subjects using vitamin D supplements exceeding 800 IU per day or active vitamin D drugs (Rocaltrol or Etalpha)

• pregnancy