The needs of individual vitamin niacin by stages of growth

Stages of growth	Requirement of niacin (mg)
For children under one year	5.4
Children 1-3 years	9.0
Children 4-6 years	12.1
Children 7-9 years	14.5
Males 10-12 years	17.2
Teens ages 13-15	19.1
Teenagers 16-19 years	20.3
Adolescents 10-12 years	15.5
Adolescent girls between 13-15 years	16.2
Adolescent girls between 16-19 years	15.2
Adult males	19.8
Adult females	14.5
For pregnant women (the second half of pregnancy)	16.8
For lactating	18.2

We can get niacin: pistachio, liver, meat, fish, eggs, milk, rice, wheat.