Elysian Spirit Shield: 70% probability to reduce damage by 25%, for an average of 17.5%. The reduction saves a number of hitpoints based on dynamic factors. we can always get Runescape  service with fast delivery that brings you more satisfactorily.
1.4 Prayer points restored per potion and 3 Hit points restored per food item in runescape gold. Now apply your ratio to your inventory space limitations to find the exact number of each item to take. 
THEN you take the inverse of the reduction factor to find how many hitpoints damage you would have taken, and compare it to how much you actually do.
Example: We have 20 inventory spaces, 99 Runescape, sharks, and 4 dose prayer potions. The ideal ratio of sharks to prayer potions is 28.91 to 1, and when limited to 20 spaces, you have to take 19.34 sharks and .66 prayer potions. As you cannot have anything short of 1 inventory space of an item, round each figure. Therefore, we have 19 sharks, and 1 prayer potion with at least three doses.
The damage you would have taken to deplete all of your food or prayer is 542 hitpoints. Those 19 sharks only heal 380, so therefore the Divine saves 162 hitpoints. You can buy runescape gold service on our site.
Elysian which is far simpler. You can skip the ratio step entirely and only take an inverse/make a comparison. All you do is (Space*Hitpoints per food item)/.825 rs gold. Then compare. For the same inventory, you have 20 sharks