Vitamin D Enriched Meat Project (Acute Study)

Bioavailability of Vitamin D-enriched Pork and Chicken in Comparison to a Vitamin D Supplement in Healthy Adults: an Acute Study

The importance of achieving an adequate vitamin D status is widely recognised, with public health and research communities heightening their interest over recent years.

Whilst vitamin D can be synthesised following skin exposure to UV light, due to public health concerns regarding sun safety, and modern indoor lifestyles, it has become evident that endogenous synthesis may not be an effective means of maintaining an adequate vitamin D status across the year. Given the marked variation in seasonally-induced cutaneous synthesis, habitually low dietary vitamin D intakes of 2-4µg/day typically reported within nationally represented population surveys, and the generally low uptake of supplementation at the population level, it is warranted to identify alternative food-based strategies to yield greater adherence to the 10µg DRV, particularly during winter months where sunlight exposure is negligible. Commodity-based biofortification may provide an innovative and viable additional food-based approach to suboptimal vitamin D status, in combination with safe sun exposure, inclusion of natural and fortified dietary sources and/or supplementation.

Meat naturally contains vitamin D3 and 25(OH)D3, yet by manipulating feeding regimes and/ or housing environments, it is possible to improve the concentration of both metabolites in animal products. Eggs, beef and pork provide viable opportunities for the enhancement of vitamin D3 and 25(OH)D3 which contribute to an increase in total vitamin D activity (vitamin D3 + [25(OH)D3 x 5]), and therefore would be expected to positively impact vitamin D status. Albeit whilst much biofortification research has been established, less is known regarding its effectiveness at raising circulating serum 25(OH)D concentrations amongst apparently healthy adults, with the exception of some plant-based foods.

Therefore, an opportunity exists to understand the bioavailability of vitamin D-enriched pork and vitamin D-enriched chicken to increase 25(OH)D concentration.

Study Overview

• Status: Completed
• Conditions: Vitamin D Deficiency
• Intervention / Treatment: Other: Pork arm; Other: Chicken arm

• Study Type: Interventional
• Enrollment (Actual): 15
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Co.Londonderry
    • Coleraine, Co.Londonderry, United Kingdom, BT52 1SA
      • Human Intervention Studies Unit, Ulster University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• · Free-living, apparently healthy Caucasian adults

  • Aged 18-65 years at Recruitment
  • Body Mass Index (BMI) ≥18.5 and <25kg/m2
  • If consuming vitamin D supplements, willing to discontinue 4 weeks prior and for duration of study
  • Non-smokers

Exclusion Criteria:

• · Non-Caucasian adults

  • Adults <18 or >65 years at recruitment
  • Taking vitamin D supplement and not willing to discontinue vitamin D supplementation for 4 weeks prior to and for duration of study
  • Current smokers
  • Pregnant/lactating females
  • Use of tanning facilities or winter vacation planned during the intervention period to a location expected to increase cutaneous synthesis
  • Severe medical illness
  • Medications which interfere with vitamin D metabolism e.g. steroid medications (e.g. prednisone), weight loss drug orlistat (e.g. Xenical and Alli), cholesterol-lowering drug cholestyramine (e.g. Questran, LoCholest and Prevalite), seizure drugs Phenobarbital and Dilantin, anti-tuberculosis, statins or thiazide diuretics
  • Intestinal malabsorption syndrome
  • Excessive alcohol use (>14 units/ week)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: TRIPLE

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Vitamin D-enriched pork; One portion of Vitamin D-enriched pork	Other: Pork arm; The effect of 1 portion of vitamin D-enriched pork on 25(OH)D concentration in comparison to a vitamin D supplement and control pork.
PLACEBO_COMPARATOR: Control pork; One portion of control pork	Other: Pork arm; The effect of 1 portion of vitamin D-enriched pork on 25(OH)D concentration in comparison to a vitamin D supplement and control pork.
ACTIVE_COMPARATOR: Vitamin D supplement; Equivocal dose of Vitamin D supplement	Other: Pork arm; The effect of 1 portion of vitamin D-enriched pork on 25(OH)D concentration in comparison to a vitamin D supplement and control pork.
EXPERIMENTAL: Vitamin D-enriched chicken; One portion of Vitamin D-enriched chicken	Other: Chicken arm; The effect of 1 portion of vitamin D-enriched chicken on 25(OH)D concentration in comparison to control chicken.
PLACEBO_COMPARATOR: Control chicken; One portion of control chicken	Other: Chicken arm; The effect of 1 portion of vitamin D-enriched chicken on 25(OH)D concentration in comparison to control chicken.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in vitamin D concentration	Vitamin D3, vitamin D2, 25(OH)D3, 25(OH)D2) (nmol/L) in serum/plasma	Change over 24 hours (baseline (0 hr), 1.5, 3, 6, 9, 24-hour)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Calcium serum concentrations	Adjusted calcium	Monitored over 24 hours (baseline (0 hr), 1.5, 3, 6, 9, 24-hour)
Parathyroid hormone (PTH) concentration	Plasma levels	Change over 24 hours (baseline (0 hr), 1.5, 3, 6, 9, 24-hour)

Collaborators and Investigators

• Sponsor: University of Ulster
• Collaborators: Devenish Nutrition, Lagan House, 19 Clarendon Road, Belfast, BT1 3BG; Agri-Food and Biosciences Institute (AFBI), 18a Newforge Lane, Belfast, BT9 5P

Study record dates

Study Major Dates

• Study Start (ACTUAL): January 16, 2020
• Primary Completion (ACTUAL): April 10, 2020
• Study Completion (ACTUAL): April 10, 2020

Study Registration Dates

• First Submitted: December 18, 2019
• First Submitted That Met QC Criteria: December 19, 2019
• First Posted (ACTUAL): December 20, 2019

Study Record Updates

• Last Update Posted (ACTUAL): June 14, 2021
• Last Update Submitted That Met QC Criteria: June 11, 2021
• Last Verified: June 1, 2021

More Information

Terms related to this study

• Keywords: Vitamin D; Adults; Crossover; Bioavailability; RCT; Pork; 25 hydroxyvitamin D; Chicken
• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency
• Other Study ID Numbers: REC/19/0040

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