Tests for vitamin 25 (OH) D3 levels and vitamin D3 metabolism
Vitamin D3 has extremely important functions in our body. Its metabolism is complicated, so we will not go into too intricate details. Generally speaking, it requires the presence of enzymes in organs such as skin, liver and kidneys. Vitamin D3 can generally be synthesized by itself, in the skin. The body can generally produce vitamin D3 itself – it synthesizes it in the skin, with the help of sunlight. So it could not be called vitamin, if not for one “but”:
In our climatic conditions, for the average person, it is practically impossible to expose the body to solar radiation that would provide our body with a sufficient dose of vitamin D3, even in the sunny months. And thus – without supplementation, we condemn ourselves to a shortage of this very important nutrient. What difference does it make? Unfortunately, large … Vitamin D3 is necessary to regulate the metabolism of every cell in our body.
Dosage of vitamin D3 should always be done under the control of its concentration in the blood, which should be 50-70ng / ml. There is no universal dose that will ensure optimal concentration for each patient, and the possibility of an overdose requires regular testing of its level during supplementation.
Due to the fact that the most active form of vitamin D, i.e. calcitriol, occurs in the blood in a very low concentration and for a fairly short time (the half-life of this molecule is about 7 hours), determination of its level in the blood would be very difficult, expensive and burdened with a significant measurement error.
In practice, the concentration of compounds that the body will only transform into ready-made vitamin D3 is determined, as well as the concentration of vitamin D breakdown products. Their levels are determined by LC-MS / MS (high-performance liquid chromatography coupled with mass spectrophotometry). It is currently the most advanced way to determine vitamin D in Poland, and this method is used to test the level of Vitamin D in our facility.
An extremely important conclusion from this method is to compare the ratio of vitamin D2 to D3. Thanks to this, we know the answer to the question of how quickly a given patient breaks down vitamin D and how high doses of vitamin D3 should supplement.