Vitamin D (fat-souble) Flashcards
What are the two distinct forms of vitamin D? Give a explanation.
• Cholecalciferol (vitaminD3) is the natural form of thr vitamin ocurring in foods. It is formed by the action of sunlight on 7- dehydocholesterol in skin of humans and animals
• Ergocalciferol (vitamin D2) is a synthetic form of the vitamin which has the same activity as the naturl vitamin. It is producer by the uktra violet irradition of ergosterol. a compound which can be extracted from yeast.
What are the sources of Vitamin D?
It is best soure found in animal sources such as fish liver oil, oily fish, eggs, butter, liver and cheese. Additionally Margarine, low fat spreads and breakfast cereals which is enriched with vitamin D is also a good source
Whats the source of Vitamin D that is not a food source?
𝐬𝐮𝐧𝐥𝐢𝐠𝐡𝐭. Although the amount of vitamin D synthesised also depends on the degree of pigmentation on the skin, on darker-skinned people less synthesis occurs.
What is the deficiency of Vitamin D in children?
Children will develop 𝐫𝐢𝐜𝐤𝐞𝐭𝐬. This results in the failure to absorb calcium and softeninv of the bones. The long bones 𝐛𝐞𝐧𝐝 under the weight, knock - knees and bow legs are typical symptoms of rickets.
What was the causes of a definicency
• not consuming enough in the diet e.g through fortified margarines, oily fish or milk
• strict vegetarian diet and not seeking out alternatives to animal sources
• low level of vitamin D in infants formula milk
• absorbtion may be hindered due to malabsorption conditions of the intestine
• high alcohol consumption
• skin synthesis can result in a deficiency of Vitamin D. not having rnough sun exposure due to being housebound for example the sick or elderly. Having sun cream on, blocking your face from sun and covering your face (could be for ethnic reasons)
What is the deficiency of Vitamin D in adults
𝐨𝐬𝐭𝐞𝐨𝐦𝐚𝐥𝐚𝐜𝐢𝐚, a condition in which the bones become soft, weak and painful. Some cases have occurrd in this country especially among elderly housebound women
Advice for older people
• get supplementation especially if in housebound (aim to have 10ug per day)
• encouraged to get outside in the sun
• consume butter, eggs, milk and oily fish
• choose fortified foods such as breakfast cereals and spreading fats.
advice for pregnant ladies
Vitamin D regulates the amount of calcium and phosphate in the bify needed to keep bones and teeth heslthy so it is important for pregnant ladies.
• recieve supplements (aim for 10ug per day)
• exposure to sunlight
^ also essential to vegans
use of supplementation pros
• It can be particularly useful for premature infants who have a particularly high requirement just after birth
• In children, low levels of vitamin D are found in formula milk and the weaning diet.
Not enough exposure to the sun or use of sunblock can all prevent vitamin D being synthesized therefore this group particularly benefit from supplementation
• For adults, those who are pregnant during the winter months, who live in the northern latitudes or who are of Asian origin may have less sun exposure. Also in adults a high alcohol intake may result in vitamin D being excreted by adults
• Older people (see points above) but supplementation is essential if they are housebound or institutionalized as they will not get enough Vitamin D exposure from the sun. Also the efficiency of Vitamin D synthesis in the skin declines with age as the skin becomes thinner and contains less of the vitamin D precursor
use of supplementation cons
Too high an intake of vitamin D is harmful as it leads to excessive amounts of calcium being deposited in the soft tissues such as the kidneys. Hypervitaminosis D can result in kidney damage. Vitamin D intakes should be controlled, particularly in young children, and vitamin supplements used only in recommended amounts.
recommended intake
over 65 years - 10ug
0 - 6 months - 8.5ug
6 months to 3 years - 6ug
