An independent statistician will produce the randomization list allocating individual study numbers to vitamin D or placebo within variable blocks of study numbers. This list will be used by the sourcing Pharmacy Department of AKU Hospital in Karachi to produce individual single dose sealed 1ml syringes for each child labeled with one study number. There will be no characteristics that would distinguish vitamin D dissolved in olive oil from the olive oil placebo in the syringes; there are no known side-effects that will distinguish those taking vitamin D from placebo.Oil from the syringes will be dropped in the mouth of each child at dozing. During the dosing weeks, Fieldworkers will receive 10 syringes each day with consecutive study numbers to be used that day and checks will be conducted in the evening. Thus Fieldworkers will only ever have 10 single doses in their possession, minimizing the possibility of mis-dosing.