Dried Purple Laver (Nori) as a Food Source of Vitamin B12 in Vegetarians

The Bioavailability of Vitamin B12 From Nori in Vegetarians: a Dose Response Study

This is an intervention study aiming to understand the bioavailability of vitamin B12 from nori for vegetarians.

Study Overview

• Status: Completed
• Conditions: Vitamin B 12 Deficiency
• Intervention / Treatment: Other: Dried purple laver (Nori)

Detailed Description

Thirty vegetarian participants will be randomly assigned to one of three intervention arms: (1) 5g of nori (4 sheets, containing 2.4μg vitamin B12), (2) 8g nori (7 sheets, containing 4μg vitamin B12), (3) control group (no nori). At baseline and end of 4 weeks, participants will be measured on serum vitamin B12, methylmalonic acid, holotranscobalamin, homocysteine and folate.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Taiwan
  • New Taipei City, Taiwan, 24205
    • Department of Nutritional Science, Fu-Jen Catholic University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 56 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Vegetarians (including vegan, ovo-vegetarian, lacto-vegetarian, lacto-ovo vegetarian)
• Duration of the vegetarian diet: at least 1 year
• Aged 20-60 years old
• Have not taken vitamin B12 or folate supplement within 1 year
• Willing to adhere to study intervention and be tested for vitamin B12 related biomarkers.
• Familiar with LINE application on smartphone

Exclusion Criteria:

• Any disease or surgery that affects the vitamin B12 status (Pernicious anemia, Gastrointestinal disease and surgery, Pancreatic diseases, Chronic kidney disease)
• Hyperthyroidism
• Previous adverse reaction to nori
• Have taken antacid or metformin in the past 1 week
• Alcoholic and not willing to abstinence from alcoholic beverages

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control; No intervention
Experimental: 2.4μg vitamin B12; Participants need to consume 4 sheets (5g) of dried purple laver (Nori) daily for 4 weeks.	Other: Dried purple laver (Nori); Dried purple laver (Nori) that has been test to have bioactivity vitamin B12 will be given for intervention groups.
Experimental: 4μg vitamin B12; Participants need to consume 7 sheets (8g) of dried purple laver (Nori) daily for 4 weeks.	Other: Dried purple laver (Nori); Dried purple laver (Nori) that has been test to have bioactivity vitamin B12 will be given for intervention groups.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in holotranscobalamin in 4 weeks	Assessing the change in serum holotranscobalamin after consuming varying doses of nori	4 weeks (Week 4 - Baseline)
Change in methylmalonic acid in 4 weeks	Assessing the change in serum methylmalonic acid after consuming varying doses of nori	4 weeks (Week 4 - Baseline)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in serum vitamin B12 concentration in 4 weeks	Assessing the change in serum vitamin B12 after consuming varying doses of nori	4 weeks (Week 4 - Baseline)
Change in homocysteine in 4 weeks	Assessing the change in serum homocysteine after consuming varying doses of nori	4 weeks (Week 4 - Baseline)

Collaborators and Investigators

• Sponsor: Fu Jen Catholic University
• Investigators: Principal Investigator: Tina Hsueh-Ting Chiu, PhD, Fu-Jen Catholic University, Department of Nutritional Science

Publications and helpful links

General Publications

• Rizzo G, Lagana AS, Rapisarda AM, La Ferrera GM, Buscema M, Rossetti P, Nigro A, Muscia V, Valenti G, Sapia F, Sarpietro G, Zigarelli M, Vitale SG. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients. 2016 Nov 29;8(12):767. doi: 10.3390/nu8120767.
• Chiu THT, Kao YC, Wang LY, Chang HR, Lin CL. A Dietitian-Led Vegan Program May Improve GlycA, and Other Novel and Traditional Cardiometabolic Risk Factors in Patients With Dyslipidemia: A Pilot Study. Front Nutr. 2022 Mar 24;9:807810. doi: 10.3389/fnut.2022.807810. eCollection 2022.
• Takenaka S, Sugiyama S, Ebara S, Miyamoto E, Abe K, Tamura Y, Watanabe F, Tsuyama S, Nakano Y. Feeding dried purple laver (nori) to vitamin B12-deficient rats significantly improves vitamin B12 status. Br J Nutr. 2001 Jun;85(6):699-703. doi: 10.1079/bjn2001352.
• Suzuki H. Serum vitamin B12 levels in young vegans who eat brown rice. J Nutr Sci Vitaminol (Tokyo). 1995 Dec;41(6):587-94. doi: 10.3177/jnsv.41.587.
• Schwarz J, Dschietzig T, Schwarz J, Dura A, Nelle E, Watanabe F, Wintgens KF, Reich M, Armbruster FP. The influence of a whole food vegan diet with Nori algae and wild mushrooms on selected blood parameters. Clin Lab. 2014;60(12):2039-50. doi: 10.7754/clin.lab.2014.140527.
• Rauma AL, Torronen R, Hanninen O, Mykkanen H. Vitamin B-12 status of long-term adherents of a strict uncooked vegan diet ("living food diet") is compromised. J Nutr. 1995 Oct;125(10):2511-5. doi: 10.1093/jn/125.10.2511.
• Watanabe F, Yabuta Y, Bito T, Teng F. Vitamin B(1)(2)-containing plant food sources for vegetarians. Nutrients. 2014 May 5;6(5):1861-73. doi: 10.3390/nu6051861.

Study record dates

Study Major Dates

• Study Start (Actual): November 7, 2022
• Primary Completion (Actual): March 31, 2023
• Study Completion (Actual): March 31, 2023

Study Registration Dates

• First Submitted: November 4, 2022
• First Submitted That Met QC Criteria: November 10, 2022
• First Posted (Actual): November 14, 2022

Study Record Updates

• Last Update Posted (Actual): June 1, 2023
• Last Update Submitted That Met QC Criteria: May 30, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: Vitamin B12; Vegetarian diet; Purple laver (Porphyra sp.); Nori
• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin B Deficiency; Vitamin B 12 Deficiency
• Other Study ID Numbers: FuJenCU

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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