Complex sentence: Cholecalciferol is produced industrially for use in vitamin supplements and to fortify foods by the ultraviolet irradiation of 7-dehydrocholesterol extracted from lanolin found in sheep's wool.
Split into simpler sentences: Cholecalciferol is produced industrially for use in vitamin supplements and to fortify foods. It is produced by the ultraviolet irradiation of 7-dehydrocholesterol extracted from lanolin found in sheep's wool.