1. Stellenbosch University; Division of Human Nutrition; Francie van Zijl Drive Tygerberg Western Cape South Africa 7505
2. University of the Witwatersrand; Wits Reproductive Health and HIV Institute (WRHI), Faculty of Health Sciences; Johannesburg South Africa
3. Stellenbosch University; Faculty of Medicine and Health Sciences; PO Box 19063 Tygerberg South Africa 7505
4. South African Medical Research Council; South African Cochrane Centre; PO Box 19070 Tygerberg Western Cape South Africa 7505