Where does Vitamin D come from?

There are two natural sources of Vitamin D - it can be produced by the skin with the help of sunlight or it can be absorbed from the diet. Vitamin D can also be taken as a supplement - but this can lead to serious illness if not appropriately handled. Other vitamins (like Vitamin C) don't share in these dangers and can be taken in excess. But Vitamin D should always be carefully used under the direction of a physician. 

Why do we need Vitamin D?

Vitamin D's only purpose is to aid in absorption of calcium from the diet. This happens in our intestines where Vitamin D is an absolute necessity for proper calcium absorption. Many products that supplement calcium have vitamin D in them (including milk, most calcium supplements). If you add more vitamin D, then you will absorb more calcium from intestines and blood calcium levels will rise. 

Can too much Vitamin D be harmful?

Yes! Since Vitamin D increases calcium absorption, then giving vitamin D to someone with high calcium can make that situation even worse! In fact, with very high levels of blood calcium, giving Vitamin D can be dangerous - even life threatening! Conversely, when primary hyperparathyroidism is present a low vitamin D level can be protective - not allowing high calcium to get even worse! The body will decrease vitamin D so that calcium absorption slows down. 

When is the right time to give Vitamin D?

True vitamin D deficiency will result in low calcium - because vitamin D helps us absorb calcium from our diet. So, if the blood calcium level is low then vitamin D would be a good thing to add! 

Can low vitamin D cause a high calcium?

No! Low vitamin D never causes high calcium - it can't! That's because vitamin D is required for proper uptake of calcium in our intestines. 

Can low vitamin D cause a low calcium?

Yes! Low vitamin D causes a low absorption of calcium - it can't do anything else (including causing a high absorption)!