Vitamin D₃supplementation in Batswana children and adults with HIV: a pilot double blind randomized controlled trial. oleh Andrew P Steenhoff, Joan I Schall, Julia Samuel, Boitshepo Seme, Marape Marape, Bakgaki Ratshaa, Irene Goercke, Michael Tolle, Maria S Nnyepi, Loeto Mazhani, Babette S Zemel, Richard M Rutstein, Virginia A Stallings