Little or no calcium is retranslocated from older to younger tissues (non-mobile). Even with a deficienct supply, calcium may continue to accumulate in older tissues, and the young terminal growth will be the first vegetative tissue to show symptoms of calcium deficiency. Low calcium tissue levels are associated with bitter pit, corking and poor storageability in apples, poor yield and quality in peanuts, increased blossom end rot in a variety of vegetable crops, blackheart of celery and poor development of cole crops and other leafy vegetables.
Calcium is an integral part of cell wall structure (calcium pectate) and as such affects the overall strength of plant tissues. Cell division fails under calcium deficiency. The higher the calcium level, the less disease problems you will have.
The balance betwen calcium, potassium and magnesium in a plant is very sensitive. A high level of any one is antagonistic to adequate uptake of the other two.
In the animal kingdom, calcium is essential for building normal bones and teeth. It is important in blood congulation and lactation. Enables heart, nerves and muscles to function. Calcium regulates permeability of tissue cells.