Facts & Recommendations
Vitamin D, the sunshine vitamin, includes two different types: vitamin D2 (Ergocalciferol) and vitamin D3 (Cholecalciferol). The last-named is taken as a dietary supplement.
It is interesting to note that this fat-soluble vitamin, in contrast to others, can be provided in two different ways: It can be ingested through food and synthesized by the organism when the skin is exposed to light (UVB exposure).
Mainly self-production by the skin (80-90% of the supply).
The primary food sources are cod liver oil, fatty fish (salmon, sardines, herring and mackerel), red meat, liver, egg yolk and shiitake mushrooms.
Vitamin D3 acts like a hormone. It is converted into calcitriol, which helps your organism control calcium metabolism by promoting intestinal absorption and bone mineralization.
It also helps to regulate the amount of phosphorus.
Both calcium and phosphorus support the development of bones and teeth.
Furthermore, it has been proven that vitamin D contributes to the maintenance of normal muscle function, supports the immune system plays a role in the cell division and participates in the process of insulin secretion.
During pregnancy and lactation, vitamin D3 maintains fetal development and prevents low birth weight. It promises an increased production of breast milk during lactation.
When babies are born, they are born with a vitamin D level that reflects their mother’s vitamin D level.
Vitamin D3 deficiency
According to the WHO, Vitamin D deficiency is a common problem in society. The prevalence of vitamin D3 deficiency is estimated to be 13% in Europe (2016 – ODIN).
The most important risk factors are:
- lower intensity of sunlight to which the skin is exposed (fewer outdoor activities, regular use of sunscreens with a high sun protection factor, clothing covering a large part of the body)
- reduced absorption through nutrition in old age, obesity or malabsorption.
Consequences of a vitamin D3 deficiency
Low levels of vitamin D3 are associated with a poor bone health (which can lead to osteoporosis).
A maternal vitamin D3 deficiency is associated with an increased risk of pre-eclampsia, gestational diabetes as well as a low birth weight and impairment of the baby´s bone quality.
Most countries have their own recommendations for vitamin D intake based on the sun exposure in certain population groups.
The German Federal Institute of Risk Assessment (BfR) recommends recommends using 20 µg (800 IU) as the highest vitamin D3 concentration in dietary supplements.