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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Retrospectively registered

Titles & IDs
Public title
Folate Absorption Study in Healthy Adults
Scientific title
Relative Bioavailability of Microencapsulated Reduced Folate versus Folic Acid in Healthy Adult Volunteers
Secondary ID [1] 251822 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Folate status in healthy adults 257246 0
Condition category
Condition code
Diet and Nutrition 257386 257386 0 0
Other diet and nutrition disorders

Study type
Description of intervention(s) / exposure
This randomised crossover study will be conducted in sixteen healthy adults. Participants will attend 8 morning clinics approximately 1 week apart. Participants will be assigned to one of 8 treatments each week using a balanced design; 1) placebo (methyl cellulose), 2) 0.4 mg non-microencapsulated folic acid, 3) 0.4 mg non-microencapsulated L-5-methyltetrahydrofolate (L-MTHF) 4) 0.4 mg microencapsulated folic acid with 75% stearate coating, 5) 0.4 mg microencapsulated L-MTHF with 75% stearate coating 6) 0.4 mg microencpaulsated folic acid with 25% stearate coating 7) 0.4 mg microencapsulated folic acid with 75% stearate coating in milk powder, 8) 0.4 mg microencapsulated L-MTHF with 75% stearate coating in milk powder. Treatments 1 through 6 will be given in capsule form and treatments 7 and 8 will be given in milk powder. At each visit, a venous catheter will be inserted and a baseline blood sample drawn. The participants will then be instructed to consume a capsule or milk containing the folate or placebo. Blood samples (5 ml) will be drawn every 1/4 hour for the first two hours and then every 1/2 hour for the next 2 hours and then every hour for an additional four hours. A standardized low folate breakfast and lunch will be offered between baseline and ½ hour blood collections and between the 4 and 5 hour blood collections, respectively.
Intervention code [1] 256366 0
Treatment: Other
Intervention code [2] 256677 0
Comparator / control treatment
Placebo containing no folate (see above)
Control group

Primary outcome [1] 258303 0
Plasma folate levels over eight hours after ingestion of folate or placebo. Area under the curve of plasma folate.
Timepoint [1] 258303 0
8 treatments one week apart.

At each visit a baseline blood sample will be drawn, the folate or placebo pill taken and blood collected every 1/4 hour for the first two hours and then every 1/2 hour for the next 3 hours and then every hour for an additional four hours.
Secondary outcome [1] 264001 0
Timepoint [1] 264001 0

Key inclusion criteria
- Males and Females aged 18-65 years
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Vitamin supplement users
- People with a chronic disease e.g. heart disease, diabetes
- People with allergies to milk
-Men and women with anemia at baseline. (Haemoglobin (Hb) <120 /L females <140 g/L males)
-People taking drugs know to interefere with folate metabolism (i.e. methotextrate, sulphasalazine, phenytoin, and others)

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
There are 8 different treatments. Each participant will be assigned to a random sequence. Allocation is concealed from participant but not investigator
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A random sequence generated using online randomization tool. Participants were randomized to the sequences.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 2604 0
New Zealand
State/province [1] 2604 0

Funding & Sponsors
Funding source category [1] 256875 0
Government body
Name [1] 256875 0
Advanced Foods and Materials Network (AFMNet) - Networks of Centres of Excellence (NCE)
Address [1] 256875 0
150 Research Lane
Suite 215
Guelph, ON
N1G 4T2
Country [1] 256875 0
Primary sponsor type
University of Otago
PO Box 56
Dunedin 9054
New Zealand
Secondary sponsor category [1] 256147 0
Name [1] 256147 0
University of British Columbia
Address [1] 256147 0
2205 East Mall, Vancouver, BC, V6T 1Z4
Country [1] 256147 0
Other collaborator category [1] 1220 0
Commercial sector/Industry
Name [1] 1220 0
Merck Eprova
Address [1] 1220 0
Im Laternenacker 5, 8200 Schaffhausen,
Country [1] 1220 0

Ethics approval
Ethics application status
Ethics committee name [1] 258882 0
University of Otago
Ethics committee address [1] 258882 0
Po Box 56
Dunedin 9054
New Zealand
Ethics committee country [1] 258882 0
Date submitted for ethics approval [1] 258882 0
Approval date [1] 258882 0
Ethics approval number [1] 258882 0

Brief summary
Folic acid is a form of the B-viitamin folate which is added to the food supply in several countries to prevent birth defects. While birth defects have declined in these countries there are some health concerns with exposing the entire population to folic acid for a lifetime. Other forms of folate such as reduced folates may be safer than folic acid. However, in their present form they are not as stable as folic acid and cannot be added to food. We have developed a process of protecting (microencapsulating) reduced folates so they are more stable. We need to show that these folate can be absorbed. We propose to conduct load tests in 16 people to determine if microencapsulated folates increase blood folate levels to the same extent as non microencapsulated folate.
Trial website
Trial related presentations / publications
The short-term bioavailability of microencapsulated folic acid and L-5-methyl-tetrahydrofolate

Available at
Public notes

Principal investigator
Name 31096 0
Address 31096 0
Country 31096 0
Phone 31096 0
Fax 31096 0
Email 31096 0
Contact person for public queries
Name 14343 0
Sarah Harvey
Address 14343 0
PO Box 56
Dunedin 9054
New Zealand
Country 14343 0
New Zealand
Phone 14343 0
64 3 479 5839
Fax 14343 0
Email 14343 0
Contact person for scientific queries
Name 5271 0
Tim Green
Address 5271 0
Human Nutrition
University of British Columbia, 2205 East Mall, Vancouver, BC, V6T 1Z4
Country 5271 0
Phone 5271 0
+1 604 822 0421
Fax 5271 0
Email 5271 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary