SIMI: Contribution of Cow's Milk to Iodine and Selenium Status in Women of Child-bearing Age

Sponsor

University of Ulster (Other)

Overall Status

Completed

CT.gov ID

NCT02767167

Collaborator

Dairy Council for Northern Ireland (Other), LGC Limited (Industry), University Hospital Southampton NHS Foundation Trust (Other), Northern Health and Social Care Trust (Other), Department of Agriculture and Rural Development Northern Ireland (Other), Charite University, Berlin, Germany (Other)

Enrollment

Location

Arms

Duration (Months)

26.1

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Iodine is an essential trace element necessary for the synthesis of thyroid hormones which are critical for human growth and development throughout the lifecycle. Iodine is particularly important during pregnancy and infancy for brain and neurological development. Severe iodine deficiency during pregnancy can cause severe mental impairment and stillbirth while mild-to-moderate deficiency has been associated with impaired infant development. As such, pregnant women and women of child-bearing age are particularly vulnerable to the effects of iodine deficiency.

Globally, 241 million (30%) school aged children are iodine deficient. Historically, the UK and Ireland were believed to be iodine sufficient but concern has been expressed in the last decade regarding the iodine status of the UK and Irish populations. A study of Irish women in 2004 reported 55% of pregnant women in their sample population to be moderately iodine deficient and 53% of non-pregnant women to be moderately iodine deficient. A study of UK schoolgirls found that 51% were mildly iodine deficient and 16% were moderately deficient. Importantly, the prevalence of iodine deficiency was highest in Northern Ireland where 85% of those sampled were iodine deficient.

Iodine is known to interact with selenium in the conversion of the thyroid hormone thyroxine (T4) to the metabolically active triiodothyonine (T3) hormone. Selenium is also important for immune, cardiovascular and cognitive function. Selenium status has been reported to be moderately low using pooled English data on blood selenium concentrations from 1984 to 1992. In addition, the latest National Diet and Nutrition Survey reports that selenium intakes are below recommendations for several population groups including women of childbearing age where mean selenium intakes are 76% of the recommended 60µg/day. This national survey also reported that 49% of women aged 19-64 years failed to meet the lower reference nutrient intake of 40µg/day.

Milk and dairy products are the major source of iodine for the UK population and are also a source of selenium. The contribution of milk and dairy products to iodine and selenium intakes is greatest in adult females (35% and 6% respectively). Observational evidence has repeatedly reported milk consumption to be positively correlated with iodine status and iodine intakes. Research in Iceland and New Zealand has reported that milk consumption is not associated with selenium status; however it is unknown if this is true for the UK population.

To date, no randomised controlled trial has examined the effect of milk consumption on either iodine or selenium status. The possibility of increasing iodine and selenium intake by increasing milk consumption, a widely available and consumed foodstuff, in a population group vulnerable to micronutrient deficiency should be investigated. This would add valuable data to the knowledge base for iodine, where there is ongoing debate over the most appropriate means of increasing iodine intake amongst women of childbearing age in the UK where salt iodisation, the key strategy in preventing deficiency, is not implemented.

The aim of this study is to investigate the impact of cow's milk consumption on the biological status of iodine and selenium among women of child-bearing age.

The study will be a 12 week randomised-controlled human intervention study. Participants will be randomised to consume additional semi-skimmed milk in the Following amounts, control group (0mls/day), intervention group (430mls/day or 3l per week).

Condition or Disease	Intervention/Treatment	Phase
Selenium and Iodine Status	Other: Semi-skimmed cow's milk	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

78 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Study Start Date :

Sep 1, 2015

Actual Primary Completion Date :

Dec 1, 2015

Actual Study Completion Date :

Dec 1, 2015

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Milk treatment group Semi-skimmed cow's milk + normal diet for 12 weeks	Other: Semi-skimmed cow's milk 430ml of semi-skimmed cow's milk / day for 12 weeks
No Intervention: Control group Normal diet for 12 weeks

Arm

Intervention/Treatment

Active Comparator: Milk treatment group

Semi-skimmed cow's milk + normal diet for 12 weeks

Other: Semi-skimmed cow's milk

430ml of semi-skimmed cow's milk / day for 12 weeks

No Intervention: Control group

Normal diet for 12 weeks

Outcome Measures

Primary Outcome Measures

Urinary iodine concentration [Change from baseline following 12-week intervention]

Secondary Outcome Measures

Serum thyroid hormone analysis [Baseline (week 0), mid (week 6) and post-intervention (week 12)]
Urinary creatinine analysis [Baseline (week 0), mid (week 6) and post-intervention (week 12)]
Serum selenoprotein P analysis [Baseline (week 0), mid (week 6) and post-intervention (week 12)]
Dietary iodine and selenium intake [Baseline (week 0), mid (week 6) and post-intervention (week 12)]
24-hour dietary recall
Blood pressure [Baseline (week 0), mid (week 6) and post-intervention (week 12)]
Body Mass Index [Baseline (week 0), mid (week 6) and post-intervention (week 12)]
Waist Hip ratio [Baseline (week 0), mid (week 6) and post-intervention (week 12)]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 45 Years

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Inclusion criteria
Healthy
Age 18-45 years
Females
Non smoking
No history of thyroid or gastrointestinal conditions
Not consuming thyroid medication or medication containing iodine or selenium
Willing to increase their milk consumption should they be randomised into the milk group

Exclusion Criteria:

Smoker
Pregnant, breastfeeding or planning to become pregnant during the study
Milk allergy
Non-milk consumers or vegans
Lactose intolerant individuals
Use of dietary supplements containing iodine or selenium in previous 3 months
Peri- or post-menopausal
Consume more than 250ml of milk daily

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Human Intervention Studies Unit, Ulster University	Coleraine	Co.Londonderry	United Kingdom	BT52 1SA

Sponsors and Collaborators

University of Ulster
Dairy Council for Northern Ireland
LGC Limited
University Hospital Southampton NHS Foundation Trust
Northern Health and Social Care Trust
Department of Agriculture and Rural Development Northern Ireland
Charite University, Berlin, Germany

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

University of Ulster

ClinicalTrials.gov Identifier:

NCT02767167

Other Study ID Numbers:

REC/15/0042

First Posted:

May 10, 2016

Last Update Posted:

May 10, 2016

Last Verified:

Apr 1, 2016

Individual Participant Data (IPD) Sharing Statement:

Plan to Share IPD:

Keywords provided by University of Ulster

Study Results

No Results Posted as of May 10, 2016