milk
There is more than one reason that your vitamin D is low. It could be due to lack on sunshine or poor diet.
A blood test would show if you are low in Vitamin D.
No. It, in fact, is the opposite. Vitamin D is absorbed in the intestine, converted by UV radiation in the skin, and then helps absorb Calcium into the body. Vitamin D deficiency can be caused by a few things, a diet low in Vitamin D, low sun exposure, or it could be caused by a tumor in the parathyroid gland (but if you have low Calcium, that is not possible).
Rickets
No, it can not.
With
vitamin D human skin produces vitamin D when exposed to sunlight
Top 10 Surprising Foods High in Vitamin D You Need in Your Diet
The term "vitamin D" refers to several different forms of this vitamin. ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D2 synthesized by plants. Vitamin D3 is synthesized by humans in the skin. D is the fourth letter in the Latin alphabet and the vitamin D was the fourth vitamin discovered.
No, vitamin D is not from jade stone. Vitamin D is an animal product. Good food sources of vitamin D are milk, eggs, fish, beef, etc. We can also produce vitamin D in our skin when it is exposed to ultraviolet radiation (usually from the sun).
Vitamin D
Orange juice fortified with vitamin D and milk fortified with vitamin D.