Vitamin D - Vitamin D Maria Papavasili Sabina Berdichevski...

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Unformatted text preview: Vitamin D Maria Papavasili Sabina Berdichevski Vitamin D Vitamin D refers to a group of fat-soluble secosteriods responsible for increasing intestinal absorption of calcium, iron, magnesium, phosphate, and zinc. In humans, the most important compounds in this group are vitamin D3 and vitamin D2, D2 and D3 can be ingested from the diet and from supplements.[ Vitamin D Very few foods contain vitamin D; synthesis of vitamin D in the skin is the major natural source of the vitamin. Dermal synthesis of vitamin D from cholesterol is dependent on sun exposure. Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and to prevent hypocalcemic tetany. Daily Intake RDA s Age Male Female Pregnancy Lactation 0–12 months* 400 IU (10 mcg) 400 IU (10 mcg) 1–13 years 600 IU (15 mcg) 600 IU (15 mcg) 14–18 years 600 IU (15 mcg) 600 IU (15 mcg) 600 IU (15 mcg) 600 IU (15 mcg) 19–50 years 600 IU (15 mcg) 600 IU (15 mcg) 600 IU (15 mcg) 600 IU (15 mcg) 51–70 years 600 IU (15 mcg) 600 IU (15 mcg) >70 years 800 IU (20 mcg) 800 IU (20 mcg) Sources of Vitamin D in food Food Cod liver oil, 1 tablespoon IUs per serving* Percent DV** 1,360 340 Swordfish, cooked, 3 ounces 566 142 Salmon (sockeye), cooked, 3 ounces 447 112 Tuna fish, canned in water, drained, 3 ounces 154 39 Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies) 137 34 115-124 29-31 Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV) 80 20 Margarine, fortified, 1 tablespoon 60 15 Sardines, canned in oil, drained, 2 sardines 46 12 Liver, beef, cooked, 3 ounces 42 11 Egg, 1 large (vitamin D is found in yolk) 41 10 Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) 40 10 Milk, nonfat, reduced fat, and whole, vitamin Dfortified, 1 cup Cheese, Swiss, 1 ounce 6 2 Sun exposure Most people meet at least some of their vitamin D needs through exposure to sunlight. Ultraviolet (UV) B radiation with a wavelength of 290–320 nanometers penetrates uncovered skin and converts cutaneous 7dehydrocholesterol to pre-vitamin D3, which in turn becomes vitamin D3. Season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis. Vitamin D Usage of Vitamin D Effective for: Low levels of phosphate in the blood due to an inherited disorder called familial hypophosphatemia. Low levels of phosphate in the blood due to a disease called Fanconi syndrome. Low blood calcium levels due to low parathyroid hormone levels. Low levels of parathyroid hormone can cause calcium levels to become too low Softening of the bones (osteomalacia). Taking vitamin D is effective for treating softening of the bones. Psoriasis. Applying vitamin D or to the skin treats psoriasis in some people. Rickets. Vitamin D is effective for preventing and treating rickets. A specific form of vitamin D, calcitriol, should be used in people with kidney failure. Side effects and safety Vitamin D is LIKELY SAFE when taken by mouth or given as a shot into the muscle in recommended amounts. Most people do not commonly experience side effects with vitamin D, unless too much is taken. Some side effects of taking too much vitamin D include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, vomiting, and others. Synthesis of Vitamin D The following diagram shows the metabolic pathways for the various forms and precursors of Vitamin D. Diseases and Deficiency Vitamin D deficiencies have been linked to heart disease, obesity, diabetes, osteoporosis, arthritis, cancer, and more. Vitamin D is important in preventing osteoporosis because it is needed to enable calcium absorption in the gut to maintain bone formation. Vitamin D is naturally made in our bodies when our skin is exposed to sufficiently-strong sunlight and may also be obtained through diet but from only a small number of whole-food sources, mostly of animal origin. Vitamin D Deficiency A normal vitamin D level is now so uncommon in North Americans and deficiencies are being linked to so many health problems that endocrinologists are now recommending a daily consumption from 1,500 to 2,000 IU a day for adults at risk (Journal of Clinical Endocrinology and Metabolism, July 2011, 96[7]). A person's blood should contain at least 30 ng/mL or more of 25(OH) D (the active form of vitamin D in the body) and 50 ng/mL for optimum health. The average blood serum levels for Americans is only 25 ng/mL. Resources Dr. Bruce Hollis. (n.d.). Retrieved February 25, 2017, from Office of Dietary Supplements - Vitamin D. (n.d.). Retrieved February 25, 2017, from Vitamin D and Cancer Prevention. (n.d.). Retrieved February 25, 2017, from Wardlaw, G. M., & Byrd-Bredbenner, C. (2016). Wardlaw's perspectives in nutrition. New York, N.Y: McGraw-Hill. ...
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