Various studies conducted in Indonesia have shown that administration of Vitamin A to pre-school children had decreased the mortality and morbidity rates among them. In the first study conducted in the province of Acheh in North Sumatra, a twice yearly high dose of vitamin A led to a 34% decrease in mortality. In a second study in Bogor, conducted by fortifying the nutritional additive MSG with vitamin A and distributing the product in a designated area, the mortality rate among preschool children was 45% less than in a control area. In the third study also conducted in Bogor, where vitamin A was given to lactating women 2 weeks after giving birth and then directly to the infants themselves after 5 months of age, the mortality rate was 38% lower. The prevalences of respiratory and diarrhoeal infections were statistically lower than in the control gorups. Another study on preschool children showed a two-fold increase of anti TT IgG on primary immunisation against tetanus when compared to a control group and a four-fold increase with a secondary immunisation. Other studies conducted in Bogor and other parts of the world have showed that smaller doses given more often are more effective than bigger doses given less often.