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Completed

NCT Number: NCT03272126

Importance of Dosing Regimen for the Effect of Vitamin D Supplementation

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.

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Key information

Conditions

Hypovitaminosis D Avitaminosis Deficiency Diseases Malnutrition Nutrition Disorders Nutritional and Metabolic Diseases Vitamin D Deficiency

Age range

20 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

University Hospital of North Norway

Tromsø, 9038, Norway

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Vitamin D

Drug

vitamin D given as bolus versus daily dosing

Placebo

Drug

identical looking as vitamin D

Primary outcomes

  1. Hepcidin change

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU regarding change in serum hepcidin

Secondary outcomes

  1. Difference in serum PTH after 1 month

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU regarding change in serum PTH, cathelicidin, RNA expression and micro RNA in peripheral blood, telomerase activity and the ratio between 1,25(OH)2D and 24,25(OH)2D, after 1 month

  2. Difference in micro RNA Expression after 1 month

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU

  3. Difference in serum cathelicidin after 1 month

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU

  4. Difference in RNA Expression after 1 month

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU

  5. Difference in telomerase Activity after 1 month

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU

  6. Difference in ratio between 1,24(OH)2D and 24,24(OH)2D after 1 month

    Time frame: 4 weeks

    Difference between vitamin D given as a bolus 160 000IU vs 4000 IU

Sponsors and collaborators

Lead sponsor

University of Tromso

Other

Registry information

Important dates

Study start
2017
Primary completion
2018
Study completion
2018
First posted
Sep 5, 2017
Registry last updated
May 24, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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