Comparative Effectiveness of Vitamin D and Repletion Strategies — CEDARS  

Diabetes Clinical Trial

Official title: A Comparative Effectiveness Trial of High-quality Vitamin D3 Nutritional Supplements to Replete Serum Vitamin D

Status Completed

Clinical Trial Summary

The importance of vitamin D (VitD) in the prevention and treatment of human health conditions has gained increased attention in recent years. As a result, medical providers of all categories are screening clinical VitD status frequently, yet become challenged with how to best advise patients regarding repletion of VitD status, i.e. which form of VitD replacement is most effective. It has been recognized that to achieve significant effects - serum concentrations >30ng/ml (75 nmol/ml) - it is necessary, as well as safe, to recommend substantially higher doses than were previously thought sufficient. These higher doses can be easily achieved orally. This clinical trial aims to compare absorption of three available forms of this fat-soluble vitamin, due to the potential differences in absorption of different preparations. High-quality powdered, chewable and lipid-emulsified VitD are readily available as supplements, yet these have not been systematically compared. This three-arm, randomized clinical trial will compare the difference in serum 25-hydroxycholecalciferol (25-OH)D concentration between the three arms at baseline and after random administration of one of the three VitD preparations for 12-weeks at a dosage of 10,000 IU VitD per day. The investigators hypothesize that the three forms of vitD will result in an equivalent increase in serum 25OHD.

Clinical Trial Description

VitD has numerous hormonal effects, including regulation of Ca2+ and Mg2+, as well as effects on numerous genes, including insulin and androgens. Mounting literature demonstrates associations between VitD insufficiency and cancer, diabetes and heart disease. VitD insufficiency, defined by concentration of serum 25-hydroxycholecalciferol (25-OHD) <33ng/ml (82.5 nmol/ml), is common at all latitudes; the prevalence is estimated at ~35% in "healthy" populations. VitD testing and replacement is gaining popularity in clinical practice. It is not known whether there is a difference in the effect of equivalent doses of emulsified vs. non-emulsified cholecalciferol (VitD3) supplementation, reflected by quantitative changes in serum 25-OHD. However, clinical observations revealed that in an average of 4.4 months, subjects taking 4000 iu daily of the emulsified form of cholecalciferol improved their 25-OHD levels by 6.76 ng/mL more than those taking 5,000 iu daily of the non-emulsified form. The safety of taking 10,000 IU/day has been confirmed. Taking this dose for 12 weeks should cause a robust increase in serum 25-OHD. This study will provide preliminary data comparing three high quality VitD3 supplements, one a powdered capsule, one a chewable tablet, and the other a lipid-emulsified liquid. Future studies will compare the "better" supplement to conventional VitD replacement using VitD2. ;

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Investigator), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Avitaminosis
• Diabetes
• Hypovitaminosis D
• Insulin Resistance
• Rickets
• Vitamin D Deficiency

• NCT number: NCT01524874
• Study type: Interventional
• Source: Bastyr University
• Status: Completed
• Phase: N/A
• Start date: August 2010
• Completion date: November 2011