Before looking at the possible disorders associated with lack of vitamin D, it is important that we understand the types and various roles this vitamin plays in our health. Vitamin D can also be called calciferol. It is made up of two major types; the ergocalciferol, also known as vitamin D2 and cholecalciferol also known as vitamin D3. The D3 occurs naturally in foods, for example, fish, egg yolks, liver meat, mushrooms and some cartilaginous bones. It can also be artificially formulated in supplements. In contrast, the D2 vitamin does not occur in foods; rather, it is produced by the tissues lining the skin when it is exposed to the sun radiation, usually at certain hours of the day. The similarity between both is that they are not readily available for usage and would have to undergo certain processes to be activated before being utilized by the body system. The liver and kidney are the organs that perform this activation as these vitamins, from the various sources (skin or ingested food) reach them (liver and kidney) through the blood. While in the liver vitamin D is converted to an active form known as calcidiol, in the kidney, it is changed into another active form known as calcitriol. Finally, they are transported through the blood to the various tissues where they perform important physiological activities.
Vitamin D helps in the active transport of calcium from the intestine into the bloodstream. This is necessary for maintaining normal levels of blood calcium. Through similar means phosphate concentrations are kept at normal. From the blood these elements are transported to the bones and teeth where they are incorporated in a process known as mineralization. This process adds to the strength and flexibility of bones while reducing the risks of bone fractures. In addition, studies have shown that Vitamin D supports cell growth and differentiation, immune function, reduces inflammation and neuromuscular function.
Vitamin D Deficiency symptoms
Nutrient deficiencies is said to occur when diets lack certain vital components, absorption and nutrient utilization is obstructed, there is increased need for nutrients, or excretion is increased. Similarly, vitamin D deficiency condition is said to occur; when there is inadequacy in blood (of the vitamin D) at a given time due to low intake, that is, at levels lower than normal, limited exposure to the sun radiation, inability of the liver and kidneys to convert this vitamin into its active forms, or there is obstruction in the absorption of vitamin D through the intestine into the blood. Intake of diets deficient in vitamin D has been attributed to some factors such as milk allergy, the practice of feeding only on vegetables (vegetarianism), lactose intolerance, and veganism.
Vitamin D deficiency symptoms are not restricted to any single age. Rickets often manifested in children is characterized by failure of bone tissue to incorporate the essential minerals, phosphorus and calcium, resulting in the bones and the entire skeleton becoming deformed. Other causes of rickets include limited exposure to the sun due probably to extensive use of sunscreens and placement of children in daycare programs, where they often have less outdoor activity hence are not frequently exposed to the sun.
As stated before, when there is deficiency of Vitamin D in the blood, the bones and the entire skeleton become deformed (due to lack or poor bone mineralization). Beginning with the children, their legs become deformed; there is stunted growth just as the bones are not formed properly over time as a result of lack of vitamin D. feelings of discomfort in the bones as well as muscle ache as associated symptoms usually in adults. This disorder may be referred to as osteomalacia. Other disorders associated with this vitamin deficiency in adults may be prolonged feeling of tiredness, arthritis, back pain, and feeling of pressure on some bones (chest bones). In some cases, obesity, gastrointestinal disorders and profuse sweating in the head may occur. However, these symptoms at the initial stage may be very small to be detected.
In contrast to the aforementioned, when the levels of calciferol (vitamin D) is higher than normal in the blood, there is bound to occur some physiological disorders such as; calcification of blood vessels and tissues. In the absence of vitamin D or at levels too low for the normal metabolic activities, the body responds through manifestations of some physiological disorders usually at the regions where they are needed. Pains and aches at certain muscles are symptoms prevalent in such conditions. Again, vitamin D is a vital nutrient which depends on the strength of the sun rays for production, becomes activated in the organs- liver and kidney, and distributed to the various tissues where they carry out their functions.