Vitamin D deficiency and its relationship with diseases
• Vitamin D is one of the fat-soluble vitamins, which helps the growth and strength of bones by controlling the balance of calcium and phosphorus. This vitamin also helps the metabolism of bones by increasing the absorption of phosphorus and calcium from the intestines and reducing excretion from the kidneys.
According to research conducted worldwide, about one billion people are exposed to insufficient levels of vitamin D in their blood, and it is estimated that 40 to 75 percent of all adults are vitamin D deficient.
• According to researchers, vitamin D is absorbed by the body through consumption of certain foods or exposure to sunlight.
• The daily requirement for this vitamin for each adult is 10 micrograms or a maximum of 2000 units per day, and this amount is higher in childhood and old age.
Vitamin D sources include: sun or sunlight, vegetable sources such as mushrooms, grains and some vegetables and fruits, and animal sources including butter, fish liver oil, egg yolk, cream, liver and sardines.
• sunshine:
Ultraviolet radiation to the human skin causes a substance called dehydrocholesterol to be converted into vitamin D in the kidney. People with lighter skin than those with darker skin can meet their need for this vitamin in less time spent under the sun.

Plant sources: plant sources such as edible mushrooms, grains and some vegetables and fruits
Animal sources:
including butter, cod liver oil, egg yolk, cream, liver and sardines.

Poverty and vitamin D deficiency cause some of the most common diseases, including heart disease, inflammatory bowel disease, dementia and Alzheimer’s, kidney disease, osteoporosis, type 2 diabetes and erectile dysfunction.

Heart disease: People suffering from vitamin D deficiency are 32% more at risk of heart disease than others. Vitamin D helps to improve the function of the body’s immune system and control inflammation, thereby reducing the risk of heart disease.