Optimization of Blood Levels of 25(OH)-Vitamin D in African Americans

Two-thirds of the US population, particularly African Americans (AA), is at risk for inadequate or deficient 25-hydroxy-vitamin D (25(OH)VD). Epidemiological studies demonstrate an association between better health outcomes and higher blood levels of 25(OH)VD . Randomized controlled clinical trials have shown that, while supraphysiological high doses of VD are needed to achieve adequate blood levels of 25(OH)VD, not all subjects respond to them. Recent studies have also questioned the therapeutic effects of high-dose VD supplementation. Severe VD deficiency has been associated independently with the future risk of mild cognitive impairment (MCI) and dementia. A reduction in GSH and an increase in the oxidative stress levels of serum, erythrocytes, and circulating lymphocytes has been observed in MCI and Alzheimer disease, findings similar to those in VD deficient persons. Scholarly reviews conclude that excess oxidative stress is one of the major risk factors for AD and support a potential therapeutic role for L-cysteine (LC, a GSH precursor) and vitamin D (VD) supplementation in the treatment of Alzheimer disease symptoms. This application presents the investigators' design for a randomized, double-blind, placebo-controlled clinical trial to test the hypothesis that supplementation with VD in combination with L-cysteine (LC) is more successful at optimizing the statuses of 25(OH)VD [biological signatures] and simultaneously decreasing TNF-α, IR [functional or clinical outcomes], and oxidative stress, suggesting a better therapeutic approach compared with supplementation with VD alone in AA subjects.

Study Overview

• Status: Completed
• Conditions: Vitamin D Deficiency
• Intervention / Treatment: Drug: Placebo; Drug: L-cysteine; Drug: Vitamin D; Drug: Vitamin D + L-cysteine

• Study Type: Interventional
• Enrollment (Actual): 165
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • Shreveport, Louisiana, United States, 71103
      • Louisiana State University Health Shreveport

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• African American volunteers only
• Participants between the ages of 18 and 65
• Must be In good general health
• Women with negative pregnancy tests

Exclusion Criteria:

• Subjects with Diabetes, Heart disease, Sickle Cell disease, or Epilepsy
• Subjects with serum positive pregnancy test or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Initially, all of the study subjects will be provided placebo supplementation as a placebo run-in period for one month before randomization. The placebo run-in period is meant to stabilize subjects in the study and will prevent any effect due solely to inclusion in the study. Placebo and supplement capsules will be similar in appearance, taste, texture, and smell, and will be provided by the pharmacist, who will have the codes for which subjects are assigned to which supplement or placebo. During testing, the placebo group will take two placebo capsules a day in the morning. Supplements will be taken daily with food at breakfast for 6 months, while participants continue to carry on a normal lifestyle	Drug: Placebo; Capsule ingested orally; Other Names: starch
Experimental: L-Cysteine; LC group will receive two capsules of LC daily. Supplements will be taken daily with food at breakfast for 6 months, while participants continue to carry on a normal lifestyle	Drug: L-cysteine; Capsule ingested orally; Other Names: amino acid
Experimental: Vitamin D3; VD group will take two capsules and each capsule will contain 1000 IU VD daily. Supplements will be taken daily with food at breakfast for 6 months, while participants continue to carry on a normal lifestyle	Drug: Vitamin D; Capsules ingested orally; Other Names: cholecalciferol
Experimental: Vitamin D3 and L-Cysteine; VD+LC group will take daily two capsule containing 1000 IU+500 mg LC. Supplements will be taken daily with food at breakfast for 6 months, while participants continue to carry on a normal lifestyle	Drug: Vitamin D + L-cysteine; Capsule ingested orally; Other Names: combination of vitamin D and L-cysteine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
25-hydroxy-vitamin D	Change in blood levels of 25(OH)VD	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
TNF-α	Whether any increase in vitamin D beneficially decreases insulin resistance	6 months
HOMA-IR	Whether any decrease in TNF-a beneficially decreases insulin resistance	6 months

Collaborators and Investigators

• Sponsor: Louisiana State University Health Sciences Center Shreveport

Study record dates

Study Major Dates

• Study Start (Actual): November 6, 2020
• Primary Completion (Actual): October 31, 2022
• Study Completion (Actual): October 31, 2022

Study Registration Dates

• First Submitted: June 8, 2021
• First Submitted That Met QC Criteria: June 17, 2021
• First Posted (Actual): June 25, 2021

Study Record Updates

• Last Update Posted (Actual): June 8, 2023
• Last Update Submitted That Met QC Criteria: June 6, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Insulin resistance; Alzheimer's Disease; African American;; Vitamin D
• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency; Physiological Effects of Drugs; Micronutrients; Bone Density Conservation Agents; Calcium-Regulating Hormones and Agents; Vitamin D; Cholecalciferol; Vitamins; Ergocalciferols
• Other Study ID Numbers: HRP-503

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: After completion of the study
• IPD Sharing Time Frame: 3 years
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No