we should test for following, why? please read on.
parathyroid hormone level
Calcidiol (25-hydroxyvitamin D or 25(OH)D) not Calcitriol (1,25-dihydroxyvitamin D or 1,25(OH)2D3.
according to Kazman
viewtopic.php?f=4&t=3420&hilit=vitamin+D
I think it is also important to get the 1,25 active metabolite tested, as their is literature suggesting that VDR receptor issues will cause too much 25 OH vitamin D to be transformed into the active metabolite. Will post a calculator on how to interpret 1,25 to 25 OH ratios, if 1,25 is too high it can be a sgn of autoimmune disease.
Apparently Quest in is the only company (in the U.S. anyway) that can accurately test 1,25. If the sample is not flash frozen immediately after being drawn then the 1,25 will be low.
I will dig through the pile of blood tests and post some of my readings.
www1.davita.com/diet-and-nutrition/diet-basics/vitamin-d-and-chronic-kidney-disease/a/1878
The vitamin D, calcium, phosphorus and parathyroid hormone (PTH) connection
Healthy kidneys are rich with vitamin D receptors and play a major role in turning vitamin D into its active form, 1,25-dihydroxyvitamin D or calciferol. When vitamin D is in its active form, it helps balance calcium and phosphorus in your body by controlling absorption of calcium and phosphorus from the food you eat and regulates parathyroid hormone (PTH).
When kidneys fail, their ability to activate vitamin D is lost. Without the activated vitamin D to control calcium and phosphorus levels in the blood, parathyroid hormone (PTH) will try to over compensate and go out of range.
Parathyroid hormone (PTH) is secreted by the parathyroid glands that are located in the neck near the thyroid glands. In kidney failure, the parathyroid glands may incorrectly sense that there is not enough calcium in the blood and produce excess parathyroid hormone which tells the body to pull calcium out of the bones and put it in the bloodstream. This excess of parathyroid hormone (PTH) can cause secondary hyperparathyroidism which can result in bone pain and weak bones that fracture easily. All patients with kidney failure are at risk for secondary hyperparathyroidism. For this reason, PTH levels are routinely monitored through lab work approximately every three months or more often if needed.
There are significant problems that may result with excess calcium in the blood stream. Calcium can deposit in soft tissues leaving “little rocks” in the tissue. These deposits or calcifications will never go away. The consequences of calcification are serious. If the heart becomes calcified, blood flow may be reduced, which could cause a heart attack. Calcification in the lungs can result in difficulty breathing. And, calcification in joints can cause extreme pain.
Liver and kidneys function
www1.davita.com/diet-and-nutrition/diet-basics/vitamin-d-and-chronic-kidney-disease/a/1878
When we eat plant sources of vitamin D, it is in the form of vitamin D2 or ergocalcifero
Vitamin D from sunlight, plant sources and animal sources are all turned into 25-vitamin D in the liver. 25-vitamin D is then carried from the liver to the kidneys where it is activated to 1,25-dihydroxyvitamin D or calciferol.
Many of us have been testef for 1,25-dihydroxyvitamin D only, which is low. Now we don’t know it’s because of our kidneys or the supply vitmanin D is already low from liver
which Vitamin D we should test in our blood? We should test either D2 or both D2 and D3.
if D2 is low this means liver is low in vitamin D stores and if D3 is low and D2 is normal then it will point to kidney’s activation problem.
vitamindcouncil.org/about-vitamin-d/what-is-vitamin-d/
Vitamin D’s metabolites
After vitamin D is formed in the skin or taken orally, it is metabolized into two different substances within the body: 25-hydroxyvitamin D, known as calcidiol, and 1,25-dihydroxyvitamin D, known as calcitriol.
Calcidiol (25-hydroxyvitamin D or 25(OH)D)
Calcidiol is a prehormone that is made in the liver. Because it is the body’s main storage form of vitamin D, the amount of calcidiol available to the body is what determines vitamin D status. When someone refers to “vitamin D levels” they are referring to blood calcidiol levels.
Calcitriol (1,25-dihydroxyvitamin D or 1,25(OH)2D3)
Calcitriol is made from calcidiol, in the kidneys as well as in other organs, and is the most potent steroid hormone in the human body. Referred to as “activated vitamin D,” calcitriol is said by the experts to “unlock” a cell’s DNA library. Acting through the vitamin D receptors (VDR), calcitriol controls the expression of genes, activating about two-thirds of the ones it controls, suppressing the rest. Blood calcitriol levels are not good indicators of the amount of vitamin D should never be used to determine if one is vitamin D deficient.