Explanation

Deficiency of vitamin –D causes rickets in children and osteomalacia in adults, thiamine (Vitamin-$B_{1}$) deficiency causes beri-beri in human and polyneuritis in animals, vitamin-K (phylloquinone) deficiency causes bleeding disease or haemorrhages, reduced fertility or sterility is caused by vitamin-E ( tocopherol) deficiency and pellagra is due to niacin or nicotinamide deficiency.