Magnesium is slightly mobile within the plant and can translocate from older to younger tissue under conditions of deficiency.
Deficiency symptoms of magnesium in plants include: interveinal chlorosis of older leaves, curling of leaves upward along the margins, and marginal yellowing with green "Christmas tree" area along the midrib of the leaf.
In animals, magnesium is essential for nerves and muscle activity and in bone structure. It aids in growth promotion. Magnesium has an important function in yeast fermentation.