ALRI - Vitamin D insufficiency in Indigenous infants and the risk of hospitalisa

Background:

One in five Indigenous infants are hospitalised with acute lower respiratory infections (ALRI) in their first year of life. Recent international studies suggest an association between vitamin D deficiency and ALRI despite adequate sun exposure. This study was the first to characterise vitamin D levels in Indigenous children and investigated the association between vitamin D deficiency and ALRI in this population.

Aims:

To describe vitamin D among Indigenous mothers and infants in the Northern Territory (NT) and determine whether cord blood vitamin D is associated with the risk of infant ALRI hospitalisation.

Methods:

In a cohort of Indigenous mother-infant pairs we measured vitamin D in maternal blood during pregnancy and at birth, in cord bloods and in infant blood at age 7 months. Cord blood vitamin D was the primary exposure. The primary outcome measure was ALRI hospitalisations during the first 12 months of infancy, identified using International Classification of Diseases coding.

Our research has found:

Cord blood vitamin D concentrations were approximately half that of maternal blood in the third trimester of pregnancy (~7 weeks earlier). Most (80%) cord bloods were vitamin D insufficient (<75 nmol/L) by existing guidelines and were lower among infants who were subsequently hospitalised with an ALRI.

Implications for policy and practice:

These results could inform maternal and/or infant vitamin D supplementation programs for the prevention of infant ALRI.

Future work:

Randomised controlled trials to determine the efficacy of vitamin D supplementation during pregnancy or infancy against infant ALRI’s.

Chief Investigators:

• Michael Binks
• Professor Ross Andrews
• Professor Anne Chang
• Dr Heidi Smith-Vaughan.

Contact information:

• Michael Binks

• Lungs - child health and development
• D-Kids: Vitamin D supplementation to prevent acute respiratory infections (ARIs) among Aboriginal and Torres Strait Islander children in the Northern Territory: a randomised placebo-controlled trial

Funders:

• Channel 7 – Children’s Research Foundation
• National Health and Medical Research Council post-graduate scholarship and Douglas and Lola Douglas scholarship in Medical Science - awarded to Michael Binks.

1. Binks M.J., Smith-Vaughan H.C., Bar-Zeev N., Chang A.B. & Andrews R.M. (2014). Vitamin D insufficiency among hospitalised children in the Northern Territory. Journal of Paediatrics and Child Health, 50(7), 512-8.
2. Binks M.J., Smith-Vaughan H.C., Marsh R.M., Chang A.B. & Andrews R.M. Cord blood vitamin D status and the risk of acute lower respiratory infection for Indigenous infants in the Northern Territory of Australia during their first year of life. Manuscript in preparation.