The production of vitamin D in the body is blocked by anything which blocks ultraviolet light including skin pigment, smog, fog, sunscreen, windows and hats.
Deficiency of Vitamin D
In cases of vitamin D deficiency, the body increases production of a hormone that removes calcium from the bones.
In children, this results in rickets where the bones are so soft that they become curved from supporting the weight of the body.
The equivalent in adults is osteomalacia with bone pain and tenderness and muscle weakness.
Other symptoms of deficiency include hearing loss (due to a softening of the bones in the inner ear), senile osteoporosis (where the bones become lighter and less dense) and severe tooth decay.
Elderly people may be at risk of vitamin d deficiency since they do not absorb or manufacture vitamin D in their bodies as well as younger people.
Others at risk of deficiency include alcoholics, people who don’t drink milk or get much sunlight, those with fat absorption problems and darker skinned people living in colder climates.
Vitamin D is converted in the liver and kidneys to its active form so sufferers of kidney and liver diseases may also be at risk of vitamin D deficiency.
The effect and cause of vitamin deficiency is a lack of that vitamin for which there is a deficiency.
The treatment of most vitamin deficiencies is to start taking that vitamin for which there is the deficiency.