In recent years, and especially the months around vitamin D has accumulated a lot of controversy. I decided to explore the topic and prepare a collection of information about vitamin D, based on the results of the latest research (in the bibliography is a variety of items from the 2015 and 2016). Not is based on a case study or research on the cell lines.
In the colloquial meaning of vitamin D vitamin D1, D2 and D3, you can also refer to kalcyferol for a group of vitamins (D). The use of this term is not a mistake, but it is not particularly precise. The different types have a slightly different role in what is said to be of low biological activity of vitamin D1. In turn, vitamin D2 in the liver is processed to 25-hydroxyvitamin D, which is what the blood level is when you want to check whether we have a vitamin D deficiency 🙂. Both vitamin D2 and D3 will be processed to this compound by means of an in the liver, and then in the kidneys.
Synthesis of vitamin D
Vitamin D2 (ergocalciferol), is synthesized in plants, photo-(under the influence of UVB rays) and vitamin D3 (cholecalciferol), which is synthesized in the skin of animals and humans (also under the influence of sunlight and UVB). The first transformation of vitamin D2 and D3 are followed in the liver under the influence of the enzyme 25-hydroxylase (cytochrome P450 microsomal triglyceride transfer 2R1 and mitochondrial cytochrome P450 27A1). Formed 25 (OH) D = kalcydiol (calicidiol). The second change (second hyrdoksylacja) occurs in the kidney under the influence of the 1?-hydroxylase (cytochrome P450 27B1). Our 25 (OH) D is converted to a 1.25-dihydroksywitaminy D2 or D3 (Calcitriol). The pace of change depends on the concentration of the parathyroid hormone. Importantly, both forms of 1.25-dihydrokowitaminy D (both D2 and D3) are biologically active and have the same features and performance.
Since both vitamin D2 and D3 will be zmetabolizowane to the compounds of the same activities and functions where the popularity of vitamin D3? I asked this question and I searched for satisfactory answers. It has been shown that supplementation with vitamin D3 is much more effective than vitamin D2.
- Sources of vitamin D
- Vitamin D1-mainly tran
- vitamin D2-plants and their preparations
- Vitamin D3 – products zoonotic (best: tran, egg yolk, greasy fish-eel, salmon, sardines, liver)
- Vitamin D is absorbed from the gastrointestinal tract in just 50%.
This is the best “source” vitamin D – UVB radiation triggers process synthesis of vitamin D3 in the skin. Has already 20-30 minutes spent in the Sun without filters (filters slows down the synthesis of vitamin D3 in the skin by up to 90%) of off-the-shoulder, legs and face enough to cover demand for vitamin D in 90%.
We have of which synthesize vitamin D under the influence of the Sun, we need to take care of the appropriate level of cholesterol in the body. This does not mean that you have to lie in the Sun by sliding the naan at the same time, because cholesterol is also synthesized in the body! However, if someone is suffering from a shortage of vitamin D, cholesterol is below normal-it is worth to take this into account.
The role of vitamin D
There are more and more indications that vitamin D not only works against cancer, but it can be a therapy for people already sick
increases the absorption of calcium and phosphorus in the digestive tract; Let’s look at the calcium: Calcitriol (the active form of vitamin D) is calcium transporter-moves it by the wall of the intestine into the blood. If we have enough (vitamin D), the absorption of calcium from the intestines into the blood will prevent properly. In the case of a vitamin D deficiency calcium absorption is slowed, and even deterred by! Even large amounts of calcium in the diet will not guarantee its positive effects without the proper amount of vitamin D in the bloodstream
The risk of vitamin D deficiency
the severity of the resorption of bone tissue, reducing the creation of new bone, reducing the production of bone matrix, reduction of mineralization and the reduction of mechanical resistance of bone tissue
Vitamin d niedoborW our geographical area can be produced in this way only from April to September. The rest of the year, its synthesis in the skin virtually there.
This could just be the Sun. Exposure consistent with the above recommendations would ensure a sufficient vitamin D synthesis in the skin, with food provided the correct level of 25 (OH) D levels.
The problem in our country is not only the lack of Sun, but lack of sufficient amounts of vitamin D are supplied with food. That is why so important is supplementation with vitamin D from September to April is not only important but necessary.
A study on the levels of vitamin D
How to check your vitamin D level? You should go to the lab, to give a blood sample and ask for mark sężenie 25-hydroxyvitamin D (25 (OH) D) levels. This is the best indicator of the body’s supply of vitamin d. but why? Since it is almost certain that you will have a shortage of (especially in autumn-winter).
Guidelines for vitamin D supplementation in the general population (source)
These are the recommendations of the preventive! Vitamin D should be suplementowana according to the guidelines in people alert on vitamin D deficiency (in the case of the Polish population especially from September to April).
Children and teens (1- 18 years):
a) dose 600? 1000 IU/day (15.0? 25.0? g/day) dependent on body weight during the period from September to April, or throughout the year, if the skin synthesis is insufficient
b) kids and teen obesity (> 90 week 48, for age and gender according to local data for your country) are a group of risk of vitamin D deficiency; It is recommended that supplemental 1200? 2000 IU/day (30? 50? g/day) depending on the degree of obesity in the period from September to April, or throughout the year, if the skin synthesis is insufficient.
Adults (> 18 ) and elderly)
a) dose 800? 2000 IU/day (20.0? 50.0? g/day) depending on the body weight during the period from September to April, or throughout the year, if the skin synthesis is insufficient
b) dose 800? 2000 IU/day (20.0? 50.0? g/day) in the elderly throughout the year, due to the lower efficiency of the production of vitamin D in the skin
c) obese (BMI? 30 kg/m2) should take all year dose 1600? 4000 IU/day (40? 100? g/day) depending on the degree of obesity.
It should be noted that the amount of vitamin D3 in multivitamin preparations is woefully inadequate.
PLEASE NOTE! Given doses of vitamin D are not referred to as FEATURED, and as the most likely non-toxic. No reliable source is not talking about the need for supplementation at such high doses. Remember the synthesis of skin and nutritional vitamin D sources-all + valid to provide supplementation level of wit. (D) in the body, and not limited to supplementation.
Vitamin D in applied equine doses has many allies in the Internet. During the research, I noticed that in many places repeated was “serious research udowadaniających that only above 50 00 IU per day can be talk about a toxic action. I scanned. The serious research  is a case of a 70-year olds, which rather than prescribed by your doctor 1 000 IU, decided by three months to feed a dose 50-times higher. Not dead, but toxic effect was noticeable-confusion, slurred speech, unsteady, increased fatigue, and finally acute kidney damage.