|
Vitamin D is needed for the absorption of calcium and phosphorous which are needed for healthy bones and teeth.
Vitamin D: In-depth
Vitamin D is a generic term for a group of compounds with vitamin D activity: the most important ones are those found in plants (vitamin D 2 /ergocalciferol) and those found in animal products (vitamin D 3 /cholecalciferol).
Vitamin D is the only vitamin that the body is capable of synthesising. Vitamin D 3 is synthesized in the skin upon exposure to UV- radiation.
Vitamin D is necessary for the storage of calcium and phosphorous in the bones thus providing healthy mineralization of the skeleton. In addition to this it regulates the calcium supply and the metabolism of phosphorous.
The body cannot store large amounts of vitamin D even though it is fat-soluble.
The storage and preparation of foods containing vitamin D does not affect the activity of the vitamin. Vitamin D is heat-stable up to 180°C (356°F).
Vitamin D: Requirement, deficiency, oversupply
Recommended intake of vitamin D according to the DGE* |
Age |
Men |
Women |
19 - 25 |
5 µg |
5 µg |
25 - 51 |
5 µg |
5 µg |
51 - 65 |
5 µg |
5 µg |
over 65 |
10 µg |
10 µg |
*Deutsche Gesellschaft für Ernährung - a German Nutrition Society.
The vitamin D provided by sunlight meets approximately 80-90% of the body's requirement (10 Minutes of sun exposure on the face and arm each day is sufficient). The only people that need a dietary intake of vitamin D are those that do not get a lot of sun exposure.
A long-term vitamin D deficiency can lead to changes in the bone tissue and the nervous system for e.g. rickets in children and osteomalacia (soft bones) in adults.
An overdose of vitamin D is not caused by excessive sun exposure or the consumption of vitamin D rich foods. An overdose is only caused by the use of vitamin D supplements.
An overdose of vitamin D causes an increase of the calcium concentration in the blood which leads to severe organ damages as a result of hypercalcemia with the following symptoms: heart problems, frequent urination and thirst, nausea and vomiting, kidney stones and kidney calcification (calcium-deposits in the kidneys and the ureter).
top  |
Vitamin D in food
Vitamin D is generally found in very few foods. Only fatty types of fish such as salmon, herring and mackerel or cod-liver oil, cheese, eggs and margarine with added vitamin D contain substantial amounts of the vitamin.
The vitamin D requirement is mostly met by the body's own production. The dietary intake of vitamin D plays a smaller role in the vitamin provision.
Vitamin D in 100 g food:
Herring: 26.71 µg
Eel: 20 µg
Sardines: 10.75 µg
Tuna: 4.54 µg
Soft cheese: 3.13 µg
Chicken egg: 2.93 µg
Margarine 2.50 µg
Butter: 1.24 µg
Units: 1,000,000 µg = 1 g
Vitamin D is added to margarine in Germany in order to provide the population with sufficient amounts.
top
The Complete Book of Food Counts, 9th Edition: The Book That Counts It All
Prescription for Nutritional Healing, Fifth Edition: A Practical A-to-Z Reference to Drug-Free Remedies Using Vitamins, Minerals, Herbs & Food Supplements, Phyllis A. Balch CNC
Earl Mindell's New Vitamin Bible,
Earl Mindell, Hester Mundis
|
