Vitamin D is a term used to refer to a group of steroid molecules. The most useful form of Vitamin D is Calciferol and the name was given based on the revised rules of the International Union of Pure and Applied Chemists (IUPAC). There are two forms of Vitamin D that are available. The first form is Vitamin D2 or also known as Ergocalciferol, a form obtained from ergosterol commonly found in yeast and the other form of Vitamin D is Vitamin D3 (Cholecalciferol), a form obtained from cholesterol via 7-dehydrocholesterol and are commonly found in animal skin.
Most of the time, Vitamin D is referred as the sunlight vitamin because the body is only capable of producing this vitamin if the sun’s ultraviolet rays hits the skin. Amongst all the other types of vitamins and minerals, this is the only one that can be considered as a hormone because the body can produce it naturally. Vitamin D is a beneficial and important vitamin that helps a person achieve optimum health and wellness through various ways like proper calcium absorption from food, regulation of calcium level in the blood, and the excretion rate of calcium in the urine, builds and strengthens bones and teeth, improves immune system and prevents certain types of cancer. The most active form of Vitamin D is Calcitriol. Calcitriol is a product of either D2 or D3 in the kidneys that binds to a protein transcription factor that is capable of regulating gene expression.
FUNCTIONS OF VITAMIN D
- Vitamin D helps the body absorb the calcium from natural food sources which can then maintain bone density and prevent bone problems like osteopenia and osteoporosis, especially for women who surpassed their menopausal stages. Without Vitamin D, the body cannot make use of calcium.
- It can also increase the reabsorption of phosphate by the kidney tubule and affects the work of osteoblasts. Osteoblasts are the cells responsible for the formation of the bones.
RECOMMENDED DAILY ALLOWANCE OF VITAMIN D
The two forms of Vitamin D, ergocalciferol and cholecalciferol are available in vitamin dietary supplements. For adults, their RDA for Vitamin D is 200 IU daily and for pregnant, lactating women including children below 10 years of age are recommended to take 400 IU of Vitamin D a day. For teenagers and adults a maximum of 2000IU per day is needed while those with undergoing vitamin D deficiency treatment, with malabsorption syndromes, nephrotic syndrome and hepatic failure need 50,000 IU of Vitamin D a day.
BEST FOOD SOURCES OF VITAMIN D (CALCIFEROL)
The most important and the primary source of vitamin D is exposure to sunlight. But when it comes to food, fortified foods are the best sources of vitamin D like milk, fatty fish such as salmon and mackerel, cod liver oil, fish liver oil, some specific breads, cereals and egg yolks.
VITAMIN D DEFICIENCY
For adults with Vitamin D deficiency, the most common health condition that they may suffer from is osteomalacia (softening of bones), while for children it’s rickets, a condition when the bones are bowing down.
