This is a long term study on the efficacy of dietary calcium with or without probiotic strains in reducing the mean number of episodes and duration of diarrheal disease.

Inclusion Criteria:

• Apparently healthy children aged 1-6 years, with emphasize on aged 2-5 years, living permanently in low socio-economic urban areas of East Jakarta for at least 6 months
• Parents are willing to sign the informed consent and give the supplements to the children for the period of 6 months
• Capable and willing to drink liquid milk with a straw (acceptance to be tested at screening by providing a sample drink and placebo straw to be consumed under supervision for 2 days)

Exclusion Criteria:

• Calcium intake exceeding 75% of the RDA for calcium (<375 mg/d) based on a Food Frequency Questionnaire
• Currently breastfed children
• Siblings of already included children that are living in the same household, except if it is a twin sibling
• Severely malnourished with or without oedema (Weight for height-WHZ Z-score of <-3.00 SD)
• Symptoms of chronic/congenital diseases and disabilities, suspected Tuberculosis by clinical examination, and /or history of allergic disease.
• Taking (any) antibiotics during 2 weeks prior to start of the study (children will be included after 3 weeks of last antibiotic intake
• Participation in another clinical trial at the same time or 2 months prior to the start of this study
• Both mothers and other caregivers present in the family are illiterate