TweetI take magnesium glycinate. One of the most absobing and least likely to cause digestive upset. here is a chart...RDA. Of course tweak to your own needs...

Life Stage	Recommended Amount
Birth to 6 months	30 mg
Infants 7-12 months	75 mg
Children 1-3 years	80 mg
Children 4-8 years	130 mg
Children 9-13 years	240 mg
Teen boys 14-18 years	410 mg
Teen girls 14-18 years	360 mg
Men	400-420 mg
Women	310-320 mg
Pregnant teens	400 mg
Pregnant women	350-360 mg
Breastfeeding teens	360 mg
Breastfeeding women	310-320 mg