Vitamin D is a fat soluble vitamin responsible for the intestinal absorption of dietary calcium and phosphorus.
Benefits of vitamin D, including maintaining healthy bones and heart to reduce the risk of breast cancer and other cancers.
Vitamin D is essential for the proper functioning of the body role, participating in important processes such as absorption and maintaining levels of calcium, which is essential for maintaining the nervous system and proper structure bones and teeth.
Many experts agree that the daily intake of vitamin D should be between 800 and 1000 IU (A UI, unit or international, is the standard used to measure vitamins like D, A or E).
Some foods rich in vitamin D
** Salmon: Salmon is one of the foods with vitamin D. A 100 gram serving has 360 IU of vitamin D, a little less than half of the daily intake that experts recommend.
** Milk and soy milk: Many brands of milk are fortified with vitamin D. A glass of 225 grams gives you 98 UI and many brands of soy, rice and almond milk are also fortified with vitamin D. Do not forget to check labels to make sure that milk is fortified with vitamin D.
** Canned tuna in oil: Tuna in oil is another food that provides 85 grams of vitamin D. tuna sandwich or a salad will give 25 percent of the daily minimum, according to experts suggest}.
** Yogurt: Many yogurts have additional contributions of vitamin D. Some yogurts fruit flavors, for example, have about 80 IU per 100 grams.
** Cereals: Not all cereals are fortified with vitamin D, so it is necessary to check the labels. Some cereals such as Cheerios have about 40 IU of vitamin D per cup.
Sunlight enhances the transformation of provitamin D to vitamin D in the skin.
Sunlight enhances the transformation of provitamin D to vitamin D in the skin. Vitamin D is formed from two provitamins: Provitamin D3 (7-dehydrocholesterol) and animal provitamin D2 (ergosterol) of vegetable origin. Ultraviolet radiation from sunlight we receive in the skin, provitamin transform these into cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) respectively. These are transformed in the liver to 25-hydroxycholecalciferol (or calcidiol) and then in the kidney is transformed through 1-25 dihydroxycholecalciferol (or calcitriol), which is the most active vitamin D product to facilitate intestinal absorption of calcium and phosphorus and bone resorption.
Sun exposure of about 10 minutes three or four days a week ensuring adequate levels of this vitamin in the body. Vitamin D produced in the skin is stored in adipose and muscle tissue from where it is used.
Moreover vitamin D as such from food. Are rich in vitamin D oily fish, fish liver oil, margarine, egg yolk, milk and dairy products.
The recommended daily amount of vitamin D is 5 mcg / day (400 U / day). This amount ensures proper bone development in children and adolescents. In adults over 50 years is recommended to increase their intake to 10-15 mg / day. There must be 25 mg / day in children or 50 mg / day in adults.
Vitamin D deficiency in the organism causes a decrease in calcium absorption by the intestine causing calcium levels decreased blood. Consequently, the parathyroid gland increases production of parathyroid hormone (PTH). This hormone acts upon the releasing bone calcium and phosphorus salts thereof (with the risk of demineralization), and stimulating kidney phosphorus loss through urine. This series of effects aim to try to normalize calcium levels in the blood, because as has been mentioned at the beginning, this cation is essential for the proper functioning of many body functions.
It is especially important to prevent calcium deficiency in children and the elderly. Therefore, in the first it is important that a balanced diet and frequent sun exposure. In older people is more common vitamin D deficiency in young adults, and is usually due to inadequate nutrition, decreased intestinal absorption of vitamin D and renal activation of pro vitamin, along with reduced exposure sun is very common.