There are various causes of vitamin D deficiency that result in a low vitamin D level in the blood and possible health issues.
One of the main causes is insufficient sun exposure. Exposure of the skin to sunlight or ultraviolet B sunlight in particular triggers the synthesis or production of vitamin D. Basically, the process involves converting a substance in the skin cells (7-dehydrocholesterol) into the preliminary form of vitamin D3 which is also known as cholecalciferol. Insufficient exposure to the sun can be due to a variety of reasons such as overuse of sunscreen in the summer months, the long periods of time spent indoors in climates that have long cold winters and days with little sunshine, and dark skin pigmentation due to genetics or suntanned skin. Lifestyle factors play a role as well such as individuals that work indoors most of the time in an office environment for example or those who simply cannot get outdoors in order to get sufficient sun exposure for vitamin D synthesis to occur.
Vitamin D is a fat-soluble vitamin and therefore, diets that are very low in fat content can lead to low vitamin D levels in the body. In these situations there is simply not enough fat to dissolve the vitamin D that is present. A certain amount of fat is required in diets in order that vitamin D and other fat soluble vitamins and nutrients that are required by the body can be absorbed and used by the body. Certain health conditions that interfere with the absorption of dietary fat are also causes of vitamin D deficiency. More specifically, these health problems are: Crohn’s disease, cystic fibrosis, pancreatic enzyme deficiency, liver disease, and gall bladder disease. In addition to health conditions that affect fat absorption, other health ailments that affect the parathyroid gland, liver or kidneys can result in a low vitamin D level because the synthesis of active vitamin D is impaired.
Breastfeeding is one of the possible causes of vitamin D deficiency. A nursing mother is supplying her infant with a wide range of nutrients and one of those is vitamin D. Infants get very little if any sun exposure and therefore, the majority of the vitamin D needs to come from the breast milk provided by the mother. It is not unusual for both the nursing mother and the infant to have low vitamin D levels. Therefore, vitamin D supplements are often used to make up for the shortfall in vitamin D. The use of supplements for nursing mothers and infants should always be under the close supervision of a doctor.
Aging is a problem for maintaining proper vitamin D levels because it causes a reduced production of vitamin D precursors in the skin and a reduction in the ability of the organs to convert vitamin D to its active form.
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