Improvement of the Selenium Supply in a Vegan Diet by Different Selenium Sources (SelVeg)

Human Intervention Study on the Improvement of the Selenium Supply in a Vegan Diet by Different Selenium Sources

As vegans are among the individuals with the lowest serum selenium levels, the randomized controlled SelVeg study aims to address the question of whether Brazil nuts could be an adequate source of selenium for diets potentially low in selenium. For this purpose, we will investigate in individuals with a vegan or omnivorous dietary pattern how a daily selenium intervention in the form of a food (here Brazil nut butter) or an over-the-counter selenium supplement affects the selenium status.

Study Overview

• Status: Completed
• Conditions: Selenium; Diet, Vegan
• Intervention / Treatment: Other: Placebo; Dietary supplement: selenium supplement; Dietary supplement: Brazil nut

Detailed Description

The vegan diet is characterized by an exclusion of all animal foods and is associated with positive health effects. However, dietary restriction can lead to inadequate intake of both macro- and micronutrients. Selenium and zinc, among others are critical nutrients in a vegan diet. Brazil nuts represent a particularly selenium-rich plant food. In addition to selenium Brazil nuts have also relevant amounts of other trace elements, including zinc, iron and copper.

Therefore, the aim of this study is to evaluate the effect of a daily selenium supplementation in the form of Brazil nut butter in comparison to a selenium supplement. As primary outcome, the serum selenium concentration and other serum biomarkers of the selenium status will be analyzed. Additionally, serum levels of other trace elements such as zinc will be quantified. Dietary questionnaires will provide information on dietary intake of nutrients (focus on dietary fiber, zinc and phytate intake) to identify potential factors influencing selenium bioavailability.

The SelVeg study will enroll 90 healthy subjects with either a vegan (defined as exclusion of animal products) or omnivore (defined as weekly consumption of meat and/or sausage) dietary pattern. After categorizing in vegans or omnivores, participants are than randomized in one of the three intervention groups (placebo, Brazil nut or selenium supplement) and will receive 55 µg of additional daily selenium (as Brazil nut butter or tablet) or no additional selenium in case of placebo. The intervention period is 2 weeks.

• Study Type: Interventional
• Enrollment (Actual): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Thuringia
    • Jena, Thuringia, Germany, 07743
      • Friedrich Schiller University Jena

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Apparently healthy participant
• Adherence to one of following eating habit (vegan or omnivore) confirmed by food frequency protocol (5 d), lifestyle and nutrition questionnaires
• Stable eating habit for at least 1 year before enrollment

Exclusion Criteria:

• Diet other than omnivore or vegan
• Changing diet during the study period
• Baseline serum selenium concentration > 150 µg/L
• Acute or chronic disease (tumor, infection, other), gastrointestinal diseases, chronic renal disease, diseases of the parathyroids, diseases necessitating regular phlebotomies
• Nut allergy
• Pregnancy or lactation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: meat-based diet; placebo	Other: Placebo; Placebo pill
Active Comparator: meat-based diet; selenium supplement	Dietary supplement: selenium supplement; Selenium supplement containing 55 µg of sodium selenate
Active Comparator: meat-based diet; Brazil nut	Dietary supplement: Brazil nut; Brazil nut butter; consumption corresponds to a selenium intake of 55 µg/d
Placebo Comparator: vegan diet; placebo	Other: Placebo; Placebo pill
Active Comparator: vegan diet; selenium supplement	Dietary supplement: selenium supplement; Selenium supplement containing 55 µg of sodium selenate
Active Comparator: vegan diet; Brazil nut	Dietary supplement: Brazil nut; Brazil nut butter; consumption corresponds to a selenium intake of 55 µg/d

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Selenium status	Changes in serum selenium concentration [µg/L] and selenoprotein-based biomarkers (SELENOP and GPX [U/L]) after intervention	baseline and after 2 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trace element serum concentrations	Change in serum concentration of trace elements (zinc, copper, manganese, iron, potassium and calcium [µg/L]) after intervention	baseline and after 2 weeks
Anthropometric data	body mass index [kg/m2]	baseline and after 2 weeks
Mean macro- and micronutrient intake over 5 days		baseline
Dietary zinc and phytate intake	Zinc and Phytate Diet Score (= frequency index * quantity index * zinc or phytate content [mg])	6 months

Collaborators and Investigators

• Sponsor: University of Jena

Study record dates

Study Major Dates

• Study Start (Actual): March 20, 2023
• Primary Completion (Actual): June 5, 2023
• Study Completion (Actual): June 5, 2023

Study Registration Dates

• First Submitted: March 23, 2023
• First Submitted That Met QC Criteria: April 14, 2023
• First Posted (Actual): April 18, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 18, 2025
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Trace Elements; Micronutrients; Antioxidants; Protective Agents; Selenium
• Other Study ID Numbers: 2023-2913-BO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Open access publications
• IPD Sharing Time Frame: end of 2023
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No