In order to increase the supply of vitamin D, it is possible to use either vitamin D supplements or dietary supplements or special balanced diets which are subject to a prescription. Depending on the classification, vitamin D levels per preparation are different. 


When fed via vitamin D supplements, dosages up to 1,000 I.U. (international units) per dose without prescription. A distinction is made between vitamin D3 (animal vitamin D from wool / lanolin, cholecalciferol) and vitamin D2 (vegetable vitamin D from fungi, ergocalciferol). Even balanced diets may contain vitamin D. 


The daily intake of vitamin D recommended by the German Nutrition Society (DGE) is 800 I.U. This value seems far too low considering the study situation. The Canadian Pediatric Society recommends 2,000 I.E. per day for expectant mothers. The Federal Office for Risk Assessment (BfR) cites 2,000 I.E as the upper limit for daily intake. 


Studies show that with a supplementation of 2,000 I.E. the vitamin D level can be stabilized. Orthomolecular physicians recommend up to 5,000 I.U. However, the correction of a lowered vitamin D level usually does not succeed. In addition, the storage must first be filled up.


Therapeutically, vitamin D is administered in doses of up to 50,000 I.U. used. 


To optimize the supply of all vitamin D positively influenced bodily functions, a blood concentration of 40-60 ng / ml should be sought. If the vitamin D concentration is greatly reduced, the level may not be sufficiently increased by the administration of over-the-counter preparations alone. In these cases a doctor should be consulted and the level of vitamin D checked regularly.