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Vitamin D Vitamin D
The Steroidal Hormone Vitamin Complex!

"DID You Know"
In humans, the most important compounds in the Vitamin D group are vitamin D3 and vitamin D2!


What is Vitamin D?

Vitamin D is a steroid hormone that has long been known for its important role in regulating body levels of calcium and phosphorus, and in mineralization of bone. More recently, it has become clear that receptors for vitamin D are present in a wide variety of cells, and that this hormone has biologic effects which extend far beyond control of mineral metabolism.

The term vitamin D actually refers to a group of steroid molecules. Vitamin D3, also known as Cholecalciferol is generated in the skin of animals when light energy is absorbed by a precursor molecule 7-dehydrocholesterol. Vitamin D is thus not a true vitamin, because individuals with adequate exposure to sunlight do not require dietary supplementation. There are dietary sources of vitamin D, including egg yolk, fish oil and a number of plants. The plant form of vitamin D is called Vitamin D2 or Ergosterol. However, natural diets typically do not contain adequate quantities of vitamin D, and exposure to sunlight or consumption of foodstuffs purposefully supplemented with vitamin D are necessary to prevent deficiencies.

Vitamin D from the diet, or from skin synthesis, is biologically inactive. It is activated by two protein enzyme hydroxylation steps, the first in the liver and the second in the kidneys.[3] As vitamin D can be synthesized in adequate amounts by most mammals if exposed to sufficient sunlight, it is not essential, so technically not a vitamin.[2] Instead it can be considered a hormone, with activation of the vitamin D pro-hormone resulting in the active form, calcitriol, which then produces effects via a nuclear receptor in multiple locations.[2]

Cholecalciferol is converted in the liver to calcifediol (25-hydroxycholecalciferol); ergocalciferol is converted to 25-hydroxyergocalciferol. These two vitamin D metabolites (called 25-hydroxyvitamin D or 25(OH)D) are measured in serum to determine a person's vitamin D status.[8][9] Calcifediol is further hydroxylated by the kidneys and some of the immune system cells to form calcitriol (also known as 1,25-dihydroxycholecalciferol), the biologically active form of vitamin D.[10][11] Calcitriol circulates as a hormone in the blood, having a major role regulating the concentration of calcium and phosphate, and promoting the healthy growth and remodeling of bone. Calcitriol also has other effects, including some on cell growth, neuromuscular and immune functions, and reduction of inflammation.[1]

What are the benifits of Vitamin D?

There are numerous benefits that can be attributed to Vitamin D, including strengthening of bones and connective tissue, aiding in the healing of wounds, and increasing the performance of the immune system. Perhaps one of Vitamin D's best attributes is its amazing anti-oxidant ability. It protects the fluids of the body such as blood from damage by free radicals. By strengthening arterial walls, it also plays an important role in maintaining a healthy blood pressure, as well as reducing tissue damage.

Vitamin D protects the cells of the body and may prevent damage caused to them by cancer, heart disease, aging, and arthritis. Some studies printed in the Journal of Strength and Conditioning Research have shown that taking Vitamin D in doses of 1000 mg per day reduced the secretion of cortisol, allowing one?s muscles to grow and lift better. There is a multitude of clinical studies that have been conducted substantiating Vitamin D's powerful effects. We know it works for a variety of ailments and we know it works well! Some studies even show that Vitamin D reduces one?s stress level.

Who needs it and what are some symptoms of deficiency?

Vitamin D deficiency or insufficiency occurs in several other situations, which you might predict based on the synthetic pathway described above:

  • Genetic defects in the vitamin D receptor: a number of different mutations have been identified in humans that lead to hereditary vitamin D resistance.
  • Severe liver or kidney disease: this can interfere with generation of the biologically-active form of vitamin D.
  • Insufficient exposure to sunlight: Elderly people that stay inside and have poor diets often have at least subclinical deficiency. Ironically, it appears that hypovitaminosis D is very common in some of the most sunny countries in the world - the cause of this problem is the cultural dictate that women be heavily veiled when outside in public.

How much should be taken? Are there side effects?

Dosage: 400IU is the needed dose, 1000 is usually the maximum, but we advocate the use of an 2000IU's for most individuals because of todays seditary life style. Mega dosing is only used in medical treatment and only under medical supervision.

Stacks well with: Vitamin A, Calcium, Creatine, Phosphorus.

Food Sources: Tuna, mackerel, butter, sardines, salmon, kipper, egg-yolks and liver.

Vitamin D toxicity: Excessive exposure to sunlight does not lead to overproduction of vitamin D. Vitamin D toxicity is inevitably the result of overdosing on vitamin D supplements. Don't do this! Ingestion of milligram quantities of vitamin D over periods of weeks of months can be severely toxic to humans and animals. In fact, baits laced with vitamin D are used very effectively as rodenticides(poison).

Recent Studies

Vitamin D is constantly being studied today against many of the viruses and ailments of todays more toxic world. We will update our page as studies bring us the latest and most accurate information.

  • "Office of Dietary Supplements - Vitamin D". October 9, 2020. Retrieved October 31, 2020.
  • Norman AW (August 2008). "From vitamin D to hormone D: fundamentals of the vitamin D endocrine system essential for good health". The American Journal of Clinical Nutrition. 88 (2): 491S–499S. doi:10.1093/ajcn/88.2.491S. PMID 18689389.
  • Bikle DD (March 2014). "Vitamin D metabolism, mechanism of action, and clinical applications". Chemistry & Biology. 21 (3): 319–29. doi:10.1016/j.chembiol.2013.12.016. PMC 3968073. PMID 24529992.
  • MacDonald J (July 18, 2019). "How Does the Body Make Vitamin D from Sunlight?". JSTOR Daily. Retrieved July 22, 2019.
  • Holick MF, MacLaughlin JA, Clark MB, Holick SA, Potts JT, Anderson RR, et al. (October 1980). "Photosynthesis of previtamin D3 in human skin and the physiologic consequences". Science. 210 (4466): 203–5. Bibcode:1980Sci...210..203H. doi:10.1126/science.6251551. JSTOR 1685024. PMID 6251551.
  • Calvo MS, Whiting SJ, Barton CN (February 2005). "Vitamin D intake: a global perspective of current status". The Journal of Nutrition. 135 (2): 310–6. doi:10.1093/jn/135.2.310. PMID 15671233.
  • Lehmann U, Gjessing HR, Hirche F, Mueller-Belecke A, Gudbrandsen OA, Ueland PM, et al. (October 2015). "Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials". The American Journal of Clinical Nutrition. 102 (4): 837–47. doi:10.3945/ajcn.114.105395. PMID 26354531.
  • "Vitamin D Tests". Lab Tests Online (USA). American Association for Clinical Chemistry. Retrieved June 23, 2013.
  • Hollis BW (January 1996). "Assessment of vitamin D nutritional and hormonal status: what to measure and how to do it". Calcified Tissue International. 58 (1): 4–5. doi:10.1007/BF02509538. PMID 8825231. S2CID 35887181.
  • Holick MF, Schnoes HK, DeLuca HF (April 1971). "Identification of 1,25-dihydroxycholecalciferol, a form of vitamin D3 metabolically active in the intestine". Proceedings of the National Academy of Sciences of the United States of America. 68 (4): 803–4. Bibcode:1971PNAS...68..803H. doi:10.1073/pnas.68.4.803. PMC 389047. PMID 4323790.
  • Norman AW, Myrtle JF, Midgett RJ, Nowicki HG, Williams V, Popják G (July 1971). "1,25-dihydroxycholecalciferol: identification of the proposed active form of vitamin D3 in the intestine". Science. 173 (3991): 51–4. Bibcode:1971Sci...173...51N. doi:10.1126/science.173.3991.51. PMID 4325863. S2CID 35236666.
  • Wolf G (June 2004). "The discovery of vitamin D: the contribution of Adolf Windaus". The Journal of Nutrition. 134 (6): 1299–302. doi:10.1093/jn/134.6.1299. PMID 15173387.

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