A brief Overview of Vitamin D

Vitamin D is among the group of fat soluble vitamins, so it is among the greasy foods and tends to be associated with the lipids in the human body. Although a vitamin, it acts more like a hormone, because it is found in one place (the skin) and will affect other organs, small intestine, bones and kidneys. Humans can synthesize it when exposed to the sun. Other sources of vitamin D are foods and vitamin supplements. For proper use in our bodies, vitamin D requires the intervention of the liver and kidneys. In the following lines I provide a general review of vitamin D. Please take note:
Biological functions: Vitamin D is needed to keep bones strong and involved in the absorption of the minerals calcium and phosphorus into the bones. Afterwards its main function is to maintain normal levels of calcium and phosphorus in the blood and therefore allow proper calcification of bones. It also participates in regulating the immune system. Some studies have found possible benefits of vitamin D in preventing osteoporosis, regulation of neuromuscular and immune function, and blood pressure, as well as reducing inflammation and preventing certain cancers.
Food Sources: Vitamin D-fortified milk, salmon, sardines, tuna, cod liver oil, mushrooms, egg yolks, fortified products like cereals, orange juice, and margarine. As mentioned above, the sun also contributes to the production of vitamin D. Although we have to consider that many people use sunscreen, and may be exposed in a very limited manner to the sun for the prevention of skin cancer.
Deficiency: When there is a deficiency of vitamin D, calcium can not be absorbed efficiently resulting in rickets and osteomalacia. In children it is called rickets, which causes skeletal deformities. This is an on-going public health problem in developing countries. Here in the United States efforts to prevent rickets since the 30s began with the fortification of milk. In recent years there have been more reported cases of rickets, as well as an association between increased risk of cardiovascular disease and vitamin D deficiency. Vitamin D deficiency in adults is called osteomalacia, which is literally soft bones, in addition to weak bones that causes muscular weakness. Adequate intake (AI) for adults ranges from 5 to 15 micrograms / day. Groups at high risk of vitamin D deficiency are the elderly, babies who are fed exclusively with breast milk, people who have dark skin tone, or those who avoid the sun, always cover exposed skin to the sun or use sunscreen whenever they go outside their homes or offices.
Poisoning: Excess vitamin D causes calcium concentration in the blood and urine to rise above normal, forming calcium deposits in soft tissues like blood vessels and kidneys as well as cardiovascular damage. So, before you start taking mega doses of vitamin D supplements please first consult with your family doctor and then make an appointment with your dietitian for healthy personalized meal plans.
Araceli Vazquez is a registered dietitian and nutritionist with practices in Dallas. You may write to Araceli@dietgenics.com or call 972-664-0846.