Vitamins and Supplements Reviews

VitaminD

Vitamin D article:

There are two basic types of vitamin D: Ergocalciferol ( vitamin D2 ) and cholecalciferol ( vitamin D3. )

Ergocalciferol occurs when ultraviolet light from the sun hits a plant leaf. Ergosterol, the basic building block of Vitamin D in plants, is transformed into ergocalciferol. Cholecalciferol occurs when ultraviolet light hits the cells of our skin. Cholesterol is then turned into cholecalciferol. Both ergocalciferol and cholecalciferol are usually referred to as " provitamin D, " and then via the liver and the kidneys, are converted into fully active vitamin D ( which is also called calcitriol. )

Vitamin D is categorized as a fat - soluble vitamin, but it actually functions more like a hormone than a vitamin. One of the main functions of vitamin D is for it to work with parathyroid hormone ( PTH ) to maintain proper levels of calcium in the blood. When there are low levels of calcium in the bloodstream, parathyroid hormone is secreted from the parathyroid gland, PTH, which stimulates the conversion of inactive forms of vitamin D to calcitriol, the most metabolically active form of vitamin D. Calcitriol increases the calcium absorption by the intestines, increases the rate of the kidneys' calcium reabsorption, and stimulates the release of calcium from the bone. All of this helps to increase blood calcium levels. Calcitriol will also decrease the intestinal absorption of calcium and stimulate the bones to take up calcium when blood levels of calcium are too high. This helps to decrease blood calcium levels.

Another function of vitamin D is regulating cell proliferation, differentiation, and growth via regulating the blood levels of calcium. This suggests that vitamin D may play a role in the prevention and treatment of certain cancers.

People who hold dispirited levels of vitamin D in their systems will have decreased absorption of calcium and phosphorous, which will lead to a negative results on bone mineralization. Infants and children with low levels of vitamin D will usually have rickets, which is characterized by bone deformities and growth retardation. Adults with dismal levels of vitamin D may experience bone pain and / or osteomalacia ( soft bone. )

Over much intake of vitamin D in either its plant - based ( D2 ) or animal - based ( D3 ) forms can be toxic. Symptoms of toxicity include loss of appetite, nausea, vomiting, high blood pressure, kidney malfunction, and a failure to thrive. In 1997, the National Academy of Sciences set Tolerable Upper Intake Levels ( ULs ) for vitamin D as the following - infants up to 1 year old should have 25 micrograms ( mcg ) per day, while children over 1 point old, adults, pregnant women, and lactating women should own 50 micrograms ( mcg ) a generation. Individuals with hyperparathyroidism, or overactivity of the parathyroid gland, should not take supplemental vitamin D without consulting a physician, as they are at increased risk for vitamin D toxicity.

The World's Healthiest Foods Nutrient Ranking System says that the best food sources for vitamin D are shrimp, cow's milk, cod, eggs, snapper, halibut, and goat's milk. It is also recommended that you get enough sunlight to make sure you own enough vitamin D in your system.

Vitamin D is a stable compound, so cooking and long - term storage don't significantly cut vitamin D levels in food.

For more hot poop, go here:
http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp
http://en.wikipedia.org/wiki/Vitamin_D
http://www.nlm.nih.gov/medlineplus/ency/article/002405.htm
http://vitamind.ucr.edu/about.html
http://www.vegansociety.com/html/food/nutrition/vitaminD.php
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