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Been doing a lot of research on Vitamin D lately, just though I would post some of what I have been put together for those of you with interest
Vitamin D- The Sunshine Vitamin
Forms: Two forms available in supplements
Cholecalciferol is the naturally occurring form of vitamin D. Photosynthesis of 7-dehydrocholesterol in human skin occurs when it is struck by uv-b rays of sunlight (290-305 nm with highest concentration at 297 nm). ‘Pre-Vitamin D” tachysterol and lumisterol are formed in ratio depending on the exact mix of wave lengths and relative strengths of rays during exposure. Pre-Vit D is than isomerised to Vit D3 by body heat in the hours after exposure.
It is important to remember that the wrong sun (mostly uv-a rays) can be just as damaging to vit D as the right sun can be producing.
It is nessesary to have some saturated fat in your diet. Bone marrow fat and dairy fats are best to make the cholesterol that gets converted to D3. A person who has a diet too high in polyunsaturated fat and not enough saturated fat will be more apt to burn in the sun (which cuts down on the Vit D produced)
Skin D cannot be overdosed since the body has mechanisms to regulate it. Oral D can be
Calcidiol: 25(OH)D or 25D
Calcidiol (25-hydroxy vitamin D) is a prehormone in your blood that is directly made from cholecalciferol. When being tested for vitamin D deficiency, calcidiol is the blood test that is drawn.
Calcitriol: 1,25(OH)2D3or 1,25D3
Calcitriol (1,25-dihydroxy vitamin D) is made from calcidiol in the kidneys and in tissues and is the most potent steroid hormone derived from cholecalciferol, as well as the most potent steroid in the human body. Calcitriol has signifigant anti-cancer activity.
The liver and kidney help convert Vitamin D to the form best utilized by the body (D3). Once vitamin D is produced in the skin or consumed in food, it requires chemical conversion in the liver and kidney to form 1,25 dihydroxyvitamin D, the physiologically active form of vitamin D. Active vitamin D functions as a hormone because it sends a message to the intestines to increase the absorption of calcium and phosphorus. Because of this hormone status it is necessary to have a well functioning thyroid for conversion
The major biologic function of vitamin D:
- maintain normal blood levels of calcium and phosphorus
- By promoting calcium absorption, vitamin D helps to form and maintain strong bones.
- Works in concert with a number of other vitamins, minerals, and hormones to promote bone mineralization. Without vitamin D, bones can become thin, brittle, or misshapen. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults, two forms of skeletal diseases that weaken bones
- Helps to maintain a healthy immune system and help regulate cell growth and differentiation.
- Inhibit cancer cells from growing and makes those cells grow and die more like natural cells.
- inhibits the formation of excessive blood vessel growth around the cancerous tumor
- Strong correlation between sunlight and serotonin production in brain
- Increase in circulating endorphins after UVB exposure (but not UVA)
- Involved in brain function due to nuclear receptors for vitamin D being localized in neurons and glial cells. Plus genes encoding the enzymes involved in the metabolism of the vit D hormone are also expressed in brain cells.
- The reported biological effects of Calcitriol in the nervous system include the biosynthesis of neurotrophic factors and at least one enzyme involved in neurotransmitter synthesis.
- Calcitriol can also inhibit the synthesis of inducible nitric oxide syntheses and increase glutathione levels, suggesting a role for the hormone in brain detoxification pathways.
- Neuroprotective and immunomodulatory effects of this hormone have been noted several experimental models. Thus could be helpful in neurodegenerative and neuroimmune diseases.
Studies about Vit D and Serotonin production:
Effect of sunlight and season on serotonin turnover in the brain
Dr GW Lambert PhD a , C Reid PhD a, DM Kaye MBBS a, GL Jennings MBBS a and MD Esler MBBS a
Alterations in monoaminergic neurotransmission in the brain are thought to underlie seasonal variations in mood, behaviour, and affective disorders. We took blood samples from internal jugular veins in 101 healthy men, to assess the relation between concentration of serotonin metabolite in these samples and weather conditions and season. We showed that turnover of serotonin by the brain was lowest in winter (p=0•013). Moreover, the rate of production of serotonin by the brain was directly related to the prevailing duration of bright sunlight (r=0•294, p=0•010), and rose rapidly with increased luminosity. Our findings are further evidence for the notion that changes in release of serotonin by the brain underlie mood seasonality and seasonal affective disorder.
Calcitriol protects against the dopamine- and serotonin-depleting effects of neurotoxic doses of methamphetamine
.Cass WA, Smith MP, Peters LE.
Department of Anatomy and Neurobiology, MN-225 Chandler Medical Center, University of KY, Lexington, KY 40536-0298, USA. email@example.com
Repeated methamphetamine (METH) administration to animals can result in long-lasting decreases in brain dopamine (DA) and serotonin (5-HT) content. Calcitriol, the active metabolite of vitamin D, has potent effects on brain cells, both in vitro and in vivo, including the ability to upregulate trophic factors and protect against various lesions. The present experiments were designed to examine the ability of calcitriol to protect against METH-induced reductions in striatal and nucleus accumbens levels of DA and 5-HT. Male Fischer-344 rats were administered vehicle or calcitriol (1 microg/kg, s.c.) once a day for eight consecutive days. After the seventh day of treatment the animals were given METH (5 mg/kg, s.c.) or saline four times in 1 day at 2-h intervals. Seven days later the striata and accumbens were harvested from the animals for high-performance liquid chromatography (HPLC) analysis of monoamines and metabolites. In animals treated with vehicle and METH, there were significant reductions in DA, 5-HT, and their metabolites in both the striatum and accumbens. In animals treated with calcitriol and METH, the magnitude of the METH-induced reductions in DA, 5-HT, and metabolites was substantially and significantly attenuated. The calcitriol treatments did not reduce the hyperthermia associated with multiple injections of METH, indicating that the neuroprotective effects of calcitriol are not due to the prevention of increases in body temperature. These results suggest that calcitriol can provide significant protection against the DA- and 5-HT-depleting effects of neurotoxic doses of METH.
Possible disease states Vit. D affects: Heart Disease, Hypertension, Arthritis, Chronic Pain, Depression, Inflammatory Bowel Disease, Obesity, Premenstrual Syndrome, Muscular Weakness, Fibromyalgia, Crohns Disease, Multiple Sclerosis, Autoimmune Illness, as well as Cancer.
Quick Facts (From Vit D Council):
• Recent studies by Heaney et al conclude healthy men utilize between 3,000–5,000 IU of cholecalciferol a day, mostly from stores made by the summer sun. .
• In 2003, Gomez recently produced evidence that excessive secretion of the parathyroid gland, known as secondary hyperparathyroidism, is almost nonexistent when 25(OH)D levels exceed 30 ng/mL (requiring 3,000 IU of D a day).Vieth cited six studies that concluded, if the aim is to keep parathyroid hormone concentrations low, 25(OH)D levels should exceed 28 ng/mL (70 nmol/L).
• Heaney and his colleagues recently showed that calcium absorption increases as 25(OH)D blood levels increase. With blood levels of 34 ng/mL (equivalent to about 3,000 IU/day total intake), calcium absorption was 65% higher than when levels are 20 ng/mL. This implies that part of the reason humans need to take so much extra calcium is because there is widespread deficiency of vitamin D. when speaking of 25(OH)D blood levels, the authors were blunt, "We conclude that the lower end of the current reference range is set too low."
• Blood pressure is reduced significantly by ultraviolet radiation comparable to about oral intake of 3,000 IU of vitamin D a day but blood pressure is not routinely reduced by small amounts of vitamin D.
• Daily doses of 2,500 IU of vitamin D helped rheumatoid arthritis but small amounts did not.
• Infants receiving 2,000 IU a vitamin D a day were almost fully protected (relative risk 0.12) from developing type 1 diabetes 30 years later.
• 5,000 IU of vitamin D a day, along with calcium and magnesium, decreased the relapse rate in multiple sclerosis patients. Multiple sclerosis is rare around the equator.
• To our knowledge, all studies of vitamin D and fractures demonstrate reduced fracture rates, as long as 25(OH)D levels increased to more than 40 ng/mL after treatment.
• Breast milk (nature's perfect food) is deficient in vitamin D. Does this mean Paleolithic humans were supposed to expose their young to the sun (and thus to predators)? Hollis recently discovered that breast-feeding mothers need 4,000 units of vitamin D a day to sustain themselves and their infant. 2,000 units a day was not effective. It seems likely to the authors that the lack of vitamin D in human breast milk is due to widespread deficiency in mothers.
• Humans make thousands of units of vitamin D within minutes of whole body exposure to sunlight. From what we know of nature, it is unlikely such a system evolved by chance.