Dosage
Since only a part of vitamin D is absorbed through food and the other part is formed on the skin itself through the sun’s rays, it is difficult to determine a guide value for a daily dose. The amount of vitamin D produced by the body itself depends on many factors, such as skin type, place of residence and sun exposure. A daily vitamin D intake of 20 micrograms is recommended, although children and the elderly should consume more.
For infants in their first year of life, half of this amount, i.e. 10 micrograms per day, is considered the recommended guideline. By staying in the sun for about 15 to 20 minutes a day, the skin can also produce some of the vitamin D itself. A longer unprotected stay in the sun is not advisable, because after 30 minutes at the latest, enough vitamin D has been produced to stop production. Regular visits to solariums in winter can also help to keep the vitamin D level at a suitable level.
Overdose
An overdose of vitamin D is called hypervitaminosis D. The probability of developing an excess of vitamin D is very low. So little of the vitamin is absorbed through food that it is almost impossible. Even massive exposure to sunlight does not produce enough vitamin D to lead to an overdose.However, taking a large quantity of vitamin D preparations can lead to vitamin D overdosage.
In this case in the intestine increased calcium is taken up, which can be proven among other things in the blood. If the calcium quantity exceeds a certain value, cold deposits can form in the blood vessels or in the kidneys. In addition, disorders of the gastrointestinal tract can occur, which manifest themselves as nausea, vomiting, constipation or abdominal cramps.
Cardiac arrhythmia can also be triggered by an overdose of vitamin D. In children, an overdose of vitamin D leads to growth disorders and a permanent increase in body temperature. In extreme cases, too high a dose of vitamin D can lead to death. Both the overdose but also the lack of vitamin D can lead to diarrhoea. Under certain circumstances, intervention by the doctor may be necessary.