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Vitamin D is produced in the skin, not the eyes.(1) I would imagine that when those indigenous peoples were introduced to sunglasses, they were also introduced to a number of other items they had never previously known, such as tobacco, alcohol and fast food. Diseases they had no immunity to might also have played a role. The synthesis of vitamin D is ...


11

The exact value depends on a lot of things - skin tone, the time of day, latitude, how deep the shade is,... The study Vitamin D effective ultraviolet wavelengths due to scattering in shade found that the UVB radiation at 280–320 nanometers that is needed for vitamin D production dropped to levels at around 50% in a tree shade and under an umbrella. It ...


7

About 1/4 - it varies with the reflectivity of the surface, and angle of the sun. Detailed study is at http://www.ncbi.nlm.nih.gov/pubmed/20199222


5

In short: UV bulbs for reptiles and tanning beds emit mainly UV-A, which does not promote vitamin D synthesis but can promote skin cancer. UV light and vitamin D synthesis (Skin Cancer Foundation): Our bodies manufacture vitamin D when the sun's ultraviolet B (UVB) rays interact with 7-dehydrocholesterol (7-DHC) present in the skin. However, we can ...


5

If you see a low vitamin D level in conjunction with a raised PTH level, then I think you need to think secondary hyperparathyroidism (HiPTH). But since vast numbers of most western populations have lowish vitamin D levels seen even in my own clinic [3] where sun shine levels are high then it may be just co-incidental. HiPTH disease should not lower the ...


5

The sunlight through the window does not stimulate vitamin D synthesis in the skin. Sunlight and Vitamin D (PubMed): Since glass absorbs all UVB radiation, exposure of the skin to sunlight that passes through glass, plexiglass, and plastic will not result in any production of vitamin D3 in the skin. The sunlight reflected from the surfaces, ...


4

According to a couple of systematic reviews of studies, there is insufficient evidence about the lowering effect of vitamin D on blood cholesterol levels. Vitamin D, Evidence Mayo Clinic (data from Natural Standard Research Collaboration) Many studies have looked at the effects of vitamin D alone or in combination with other agents for high cholesterol,...


4

Vitamin D is produced in the skin by UV irradiation of 7-dehydrocholesterol. But vitamin D in the skin is also broken down by UV irradiation and this leads to a maximum equilibrium level of vitamin D in the skin of the order of 25,000 IU (different sources will give different figures of this maximum value, The vitamin D council says it's between 10,000 and ...


4

According to some studies, adequate vitamin D intake from foods and supplements may prevent bone weakness (osteporosis) in elderly, but according to others it may not. Efficacy of optimization of vitamin D in preventing osteoporosis and osteoporotic fractures: A systematic review (PubMed, 2006): ...vitamin D intake of 10-17.5 μg/day (400-700 IU/day) or ...


4

There are a few mechanisms at work that influence the vitamin D status for Europeans. Vitamin D is either eaten in the food, created with the help of sunlight or supplemented. Many appear to net have enough it: Humans get vitamin D from exposure to sunlight, from their diet, and from dietary supplements. A diet high in oily fish prevents vitamin D ...


3

Vitamin D is not strictly a vitamin, rather it is the precursor of one of the hormones involved in the maintenance of calcium homeostasis and the regulation of cell proliferation and differentiation, where it has both endocrine and paracrine actions. It is important to note that the most important source is the endogenous synthesis in the skin by ...


3

This has been a controversial question for many years. The current evidence suggests that sunscreen does block a part of Vitamin D production, but with negligible amounts. Studies have found that by blocking ultraviolet rays, sunscreen limits the vitamin D we produce. But the question is to what extent. A few studies have concluded that the effect ...


3

WebMD Signs and Symptoms of Vitamin D deficiency can be subtle, but can manifest as bone pain and muscle weakness. Also, excessive sweating(when not indicated due to exercise level and heat). Because of the sometimes subtle symptoms, getting appropiate screening based on risk factors and regular physician exams is important to discovering and managing ...


2

The older the animal, the greater the amount of vitamin D stored in the liver. While liver is a somewhat good source of vitamin D, it's also very high in vitamin A. A person eating liver more often than once or twice a week could possibly overload on vitamin A. Especially in the amount youd need to correct a vitamin D deficiency. Vitamin A is toxic in ...


2

It is already released in winter, and may help prevent very low levels that might otherwise be obtained. Vitamin D Stored in Fat Tissue During a 5-Year Intervention Affects Serum 25-Hydroxyvitamin D Levels the Following Year. Martinaityte I1,2, Kamycheva E1,2, Didriksen A1, Jakobsen J3, Jorde R1,2. Author information Abstract CONTEXT: Vitamin D and ...


2

I don’t know if they can be used, but they shouldn’t. Recently, sun exposure is considered more and more harmful to the skin. This is why for recommended Vitamin D levels, no sun exposure whatsoever is usually assumed, and only intake via diet considered. Because ultraviolet rays from the sun and tanning beds can cause skin cancer, the American Academy of ...


2

It appears that Vitamin D oil drops are just as effective as tablets. Well they have the oil which helps the Vitamin D absorb since D is fat soluble I guess. https://vitamindwiki.com/tiki-download_wiki_attachment.php?attId=13764&download=y We compared the effectiveness of tablets versus oil in raising S-25-hydroxyvitaminD(S-25-OHD) in plasma by re-...


1

Ideally, people should get enough vitamin D from their food. However, that's difficult to do, Many folks don't get enough of the nutrient from dietary sources like fatty fish and fortified milk. Ref: here It's not known exactly how much time is needed in the sun to make enough vitamin D to meet the body's requirements.Ref.here This is because there are a ...


1

Vitamin D deficiency can actually cause or exacerbate depression, and it can manifest itself in feelings of tiredness, persistent sadness, weakness, etc... It also prevents your bones from mineralizing so your bone density may decline and cause bone pain (as stated by WebMD). I've experienced this, and it feels like an ache deep inside your limbs. I also had ...


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