However, worldwide reports have highlighted a variety of vitamin D insufficiency and deficiency diseases. Despite many publications and scientific meetings reporting advances in vitamin D science, a disturbing realization is growing that the newer scientific and clinical knowledge is not being translated into better human health. Over the past several decades, the biological sphere of influence of vitamin D3, as defined by the tissue distribution of the VDR, has broadened at least 9-fold from the target organs required for calcium homeostasis intestine, bone, kidney, and parathyroid. As a consequence, the nutritional guidelines for vitamin D3 intake defined by serum hydroxyvitamin D3 concentrations should be reevaluated, taking into account the contributions to good health that all 36 VDR target organs can provide.
Vitamin D Vitamin D Vitamin D is a hormone produced by the kidneys that helps to control the concentration of calcium in the blood and is vital for the development of strong bones. Alternative names for vitamin D Calcitriol or 1,dihydroxyvitamin D ; ergocalciferol vitamin D2 ; cholecalciferol vitamin D3 ; calcidiol hydroxyvitamin D What is vitamin D?
Active vitamin D helps to increase the amount of calcium the gut can absorb from eaten food into the bloodstream and also prevents calcium loss from the kidneys.
Vitamin D modifies the activity of bone cells and is important for the formation of new bone in children and adults.
How is vitamin D controlled? A fall in the concentration of calcium in the bloodstream is detected by the parathyroid glandswhich then produce parathyroid hormone.
Parathyroid hormone increases the activity of the enzyme catalyst that produces active vitamin D. This increase in the concentration of calcium together with vitamin D feeds back to the parathyroid glands to stop further parathyroid hormone release. The production of vitamin D is also directly regulated by calcium, phosphate and calcitriol.
What happens if I have too little vitamin D? Vitamin D deficiency is common in the UK, probably due to lifestyle changes and lack of sun exposure. If you have severely low vitamin D levels you are unable to maintain an adequate concentration of calcium in your blood for bone growth.
This causes rickets in children and osteomalacia in adults. As the role of vitamin D as a regulator of other functions throughout the body has emerged, it has been suggested that a lack of vitamin D is linked to an inability to fight infections effectively, muscle weakness, fatigue and the development of diabetescertain cancers, multiple sclerosis, depressionheart disease, high blood pressure, and strokealthough the direct relevance and mechanisms underlying these responses remain unknown.
Oily fish such as sardines, mackerel and salmon are good dietary sources of vitamin D. In the UK, foods such as breakfast cereals and margarine are fortified with vitamin D.
Adequate exposure to sunlight is important, especially between April and October, for around 15 minutes daily. Public Health England recommends vitamin D supplements are taken by people in at risk groups for example, women who are pregnant or breast-feeding, young children and those with osteoporosis.
What happens if I have too much vitamin D? It is very rare to have too much vitamin D. If you have too much vitamin D the level of calcium in your blood may increase and this causes a condition known as hypercalcaemiawhich can cause a number of symptoms such as nausea, vomiting, constipation, tiredness, confusion, depression, headaches, muscle weakness, the need to pass urine more frequently and feeling thirsty.
However, this condition is very rare.On the basis of these studies, other investigators have demonstrated that vitamin D must be metabolized in the renal tubule to an active vitamin D hormone, 1,dihydroxy vitamin D, which is the.
3 1,25(OH) 2 D is a steroid hormone activating a nuclear transcription factor, the vitamin D receptor (VDR), which regulates the transcription of vitamin D responsive genes. 4 Despite the original misnaming of vitamin D (since it is actually a prehormone) this term has continued to be used.
Vitamin D, the kind you make on your skin, is practically not a vitamin. It is more appropriately classified as a leslutinsduphoenix.com active hormone D, calcitriol, controls calcium in vertebrates and invertebrates. Calcitriol, also called 1,dihydroxycholecalciferol, or 1alpha,dihydroxyvitamin D3, 1,dihydroxyvitamin D 3 and other variants, is the hormonally active metabolite of vitamin D which has three hydroxyl groups.
Vitamin D is a hormone the kidneys produce that controls blood calcium concentration and impacts the immune system. It is also known as calcitriol, ergocalciferol, calcidiol and cholecalciferol. Of those, calcidiol is the form doctors most commonly focus on when measuring vitamin D levels in the blood.
First we have Vitamin D which is referent to either Vitamin D3 (cholecalciferol) or Vitamin D2 (ergocalciferol).Vitamin D is the structural raw material that one or .