Lactose maldigestion--age-specific prevalence in black and Indian children.

A study was performed to determine the prevalence and age of onset of primary lactose maldigestion in healthy black and Indian children, and to determine whether this was of clinical significance. More black (22 of 44-50%) than Indian children (10 of 45-22.2%) had lactose maldigestion (P less than 0.02), the development of which was age-related and occurred earlier in blacks than in Indians; 6 of 19 black children less than 5 years old (31.6%) were lactose maldigesters, compared with 8 of 10 (80%) over 10 years old, while only 1 of 16 Indian children aged under 8 years (6.3%) were maldigesters, compared with 5 of 13 (38.5%) aged over 10 years. Most children had a very low intake of milk and lactose maldigestion was of no clinical significance to them.