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

NCT ID: NCT05814874

Last Updated: 2025-03-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 90 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-03-20
• Study Completion Date: 2023-06-05

Brief Summary

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.

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.

Conditions

Diet, Vegan; Selenium

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

meat-based diet; placebo

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Placebo pill

meat-based diet; selenium supplement

Group Type: ACTIVE_COMPARATOR

selenium supplement

Intervention Type: DIETARY_SUPPLEMENT

Selenium supplement containing 55 µg of sodium selenate

meat-based diet; Brazil nut

Group Type: ACTIVE_COMPARATOR

Brazil nut

Intervention Type: DIETARY_SUPPLEMENT

Brazil nut butter; consumption corresponds to a selenium intake of 55 µg/d

vegan diet; placebo

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Placebo pill

vegan diet; selenium supplement

Group Type: ACTIVE_COMPARATOR

selenium supplement

Intervention Type: DIETARY_SUPPLEMENT

Selenium supplement containing 55 µg of sodium selenate

vegan diet; Brazil nut

Group Type: ACTIVE_COMPARATOR

Brazil nut

Intervention Type: DIETARY_SUPPLEMENT

Brazil nut butter; consumption corresponds to a selenium intake of 55 µg/d

Interventions

selenium supplement

Selenium supplement containing 55 µg of sodium selenate

Intervention Type: DIETARY_SUPPLEMENT

Brazil nut

Brazil nut butter; consumption corresponds to a selenium intake of 55 µg/d

Intervention Type: DIETARY_SUPPLEMENT

Placebo

Placebo pill

Intervention Type: OTHER

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Jena

OTHER

Sponsor Role: lead

Responsible Party

Anna Kipp

Prof. Dr.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Friedrich Schiller University Jena

Jena, Thuringia, Germany

Countries

Germany

References

Simon R, Lossow K, Pellowski D, Kipp K, Achatz M, Klasen N, Schwerdtle T, Dawczynski C, Kipp AP. Improving the selenium supply of vegans and omnivores with Brazil nut butter compared to a dietary supplement in a randomized controlled trial. Eur J Nutr. 2025 Feb 1;64(2):74. doi: 10.1007/s00394-025-03587-z.

Reference Type: DERIVED

PMID: 39891729 (View on PubMed)

Other Identifiers

2023-2913-BO

Identifier Type: -

Identifier Source: org_study_id