Most of the vitamin D required by humans is produced by ultraviolet (UV) irradiation of the 7-dehydrocholesterol present in the skin. However, dietary intakes are critical where there is little or no exposure to sunlight.
A proportion of Vitamin D absorbed, via consumption, is converted into 25-hydroxyvitamin D in the liver, which has a very small amount of biological activity; however, further conversion by the kidney into 1,25-dihydroxyvitamin D (calcitriol) then produces the active form of vitamin D.
This active form is involved in calcium homeostasis, mainly by controlling the amount of calcium absorbed and excreted.
It is said to have:
* A direct effect on bone synthesis
* It also regulates insulin secretion and sensitivity and balances blood sugar (...hence weight loss)
* It can have a positive effect on the immune system, and known to prevent recurrent lung infections.
* It improves cognitive ability so it’s easier to concentrate and process information.
The Active Times states that
When natural sunlight hits the skin it triggers the body’s production of vitamin D. Vitamin D is also known as “the sunshine vitamin.”
It is a crucial ingredient for overall health;
* protects against inflammation,
* helps muscles,
* improves brain function and
* may even protect against cancer.
Vitamin D is negatively impacted by low or no exposure to natural sunlight and diets high in fried, processed and refined foods.
A deficiency will result in bone pain and muscle tenderness or weakness.
A deficiency may also play a contributory role in the development of osteoporosis and insulin resistance and numerous autoimmune diseases.
Vitamin D is a fat soluble vitamin and thus can be toxic. It is always best to get a blood serum baseline blood test done before commencing on any form of Vitamin D therapy.
Once you have your baseline blood serum levels checked it is easier to know what dosage of Vitamin D3 is best, a selection from 1000iu to 5000iu are widely available in various formats from capsules, to transdermal patches, and oral sprays. The recommended ‘ normal’ levels are 50 ng/mL, however, if we are going for optimal health then a level closer to, but no higher than, 80 ng/mL is suggested. Please note that blood serum levels should be checked 2x per year in order to ensure safety in use.
According to wikipedia:
Light to the eyes, primarily blue-wavelength light, is important for the entrainment and maintenance of robust circadian rhythms. Exposure to sunlight in the morning is particularly effective; it leads to earlier melatonin onset in the evening and makes it easier to fall asleep. Bright morning light has been shown to be effective against insomnia, premenstrual syndrome and seasonal affective disorder (SAD).