None listed
Conditions
Brief summary
Vitamin D is essential for mineral balance of the skeleton. In children, deficiency classically causes Rickets, leading to bone thinning and malformation. Deficiency is also associated with low bone mineral density which has potential long-term implications. Vitamin D also plays a major role in the immune system. Vitamin D is unique among vitamins as its main source is not dietary, but synthesis in the skin following exposure to UVB radiation, from sunlight. UVB radiation exposure varies based on latitude, skin colour, sunscreen use and clothing. Changes in human lifestyle including sun avoidance practices, indoor occupations and recreation, added to NZ’s geographical location at 35ºS to 47ºS, mean that children and adults cannot depend on adequate skin exposure to sunlight for vitamin D synthesis. Dietary intake is a secondary source, but there is little in foods most humans normally ingest. As opposed to many countries NZ currently has no mandatory food supplementation. Compounding this, human milk, which is advocated as the ideal fluid source for infants, has been criticised as being generally low in vitamin D and this has led some to recommend universal supplementation for breast feeding infants. One of the reasons breast milk is not a rich source of vitamin D is that many breast feeding mothers have low vitamin D status. Preliminary work from the United States suggests that daily supplementation of the breast feeding mother with high dose vitamin D can safely lead to improved vitamin D levels for both her and her nursing infant. This suggests an attractive alternative to universal supplementation of breast fed infants. Supplementing infants via their mother’s breast milk supports current WHO recommendations on the importance of breast feeding and also avoids the issue of direct supplementation of exclusively breast-fed infants which is controversial and poorly complied with by families. This study is powered to provide definitive data on clinically significant changes to baseline vitamin D levels for both the lactating mother and breast feeding infant during three arms of monthly treatment - 50000IU vitamin D3, 100000IU vitamin D3 or placebo . Results form this study will be used to inform public health policy regarding vitamin D supplementation during periods of exclusive lactation/breast feeding.
Interventions
Two intervention groups will be used. Monthly maternal oral cholecalciferol 1) 50,000 IU or 2) 100,000 IU during 4 months of exclusive lactation. A third arm receiving only placebo will be used. The first dose will be given by 2 weeks postnatal age. Dosing will consist of monthly medication in blister packs of placebo/placebo, placebo/50,000IU Cholecalciferol or 50,000IU Cholecalciferol/50,000IU Cholecalciferol as appropriate.
Sponsors
Dunedin School of Medicine
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
0 to No maximum
Healthy volunteers
Yes
Inclusion criteria
Healthy pregnant women intending to exclusively breast feed for at least 4 months.
Exclusion criteria
1) unwilling to stop taking additional postnatal supplements that contain vitamin D 2) not intending to exclusively breast feed for at least 4 months, 3) delivery prior to 37 weeks gestation, 4) Low or elevated calcium levels at baseline or 5) not willing to take vitamin D supplementation, 6) Health conditions potentially affecting vitamin D metabolism e.g. on anticonvulsants, malabsorption problems, 7) Potential subjects will also be excluded if they are planning to travel to a sunny climate during the study period.
Outcome results
None listed