Yoga exercises could stimulate the passage of (green) food and/or (originally green) bile through your bowel, and then either the food or bile would color the stool green. If stools are loose and contain undigested food, you are losing nutrients this way.
Excessive use of magnesium supplements can be toxic. The upper limit -- the highest dose a person can take -- of magnesium supplements is: 65 mg/day for children ages 1-3. 110 mg/day for children ages 4-8. 350 mg/day for adults and children ages 9 and up.
The daily recommended intake of magnesium ranges from 400 to 420 mg in men, 310 to 360 mg in women and 80 to 240 mg in children all depending on age. Signs That You May Be Deficient. In my case, a magnesium deficiency was identified through the panic and anxiety that I was working through earlier this year.