Sunshine: The Eighth Basic Health Habit and D-Mystifying Vitamin D




Exposure to sunlight causes vitamin D to be produced in your skin. But only a portion of the solar spectrum, known as ultraviolet B (UVB), has this effect. 

Other parts of the solar spectrum can have very different and even harmful effects. UVA can cause cancerous mutations, and can also break down the vitamin D formed in your skin after outdoor UVB exposure. Vitamin D is a potent defense against melanoma. Melanoma cells convert it to calcitriol, which causes tumour growth inhibition and apoptotic cell death in vitro and in vivo. New research shows that increased UVA exposures and inadequately maintained cutaneous levels of vitamin D promote melanoma.

Vitamin D, calciferol, is a fat-soluble vitamin. It is found in food, but it can also be made in your body after exposure to ultraviolet rays from the sun. Vitamin D exists in several forms, each with a different activity. Some forms are relatively inactive in the body, and have limited ability to function as a vitamin. The liver and kidney help convert vitamin D to its active hormone form.

Vitamin D plays a crucial role in the absorption and maintenance of calcium for bone health, nerve and muscle function, and blood coagulation. The major biologic function of Vitamin D is to maintain normal blood levels of calcium and phosphorus. It promotes bone mineralization in concert with a number of other vitamins, minerals, and hormones. 

The active form of vitamin D also acts as an effective regulator of cell growth and differentiation in a number of different cell types, including cancer cells. 

Vitamin D deficiency has been associated with insulin deficiency and insulin resistance.








Vitamin D Deficiency has been associated with:
  • adrenal insufficiency
  • Alzheimer's
  • allergies
  • autoimmune disorders including multiple sclerosis and rheumatoid arthritis
  • cancers of the colon, breast, skin and prostate
  • depression, seasonal affective disorder (SAD)
  • diabetes, Type 1 and 2
  • gluten intolerance, lectin intolerance
  • heart disease, hypertension, Syndrome X
  • infertility, sexual dysfunction
  • learning and behavior disorders
  • misaligned teeth and cavities
  • myopia (near-sighted)
  • obesity
  • osteopenia (low bone mineral density), osteoporosis, rickets, osteomalacia (adult rickets)
  • Parkinson's
  • PMS
  • psoriasis
  • use of corticosteroids







Vitamin D is not a vitamin. It is more appropriately classified as a pro-hormone. Not only is it a pro-hormone, it is a sunlight derived pro-hormone. The active hormone D, calcitriol, controls calcium in vertebrates. Calcium controls innumerable processes in the human body including specific responses in muscles, bones and glands. Calcitriol is a major player in genomic actions determining how our cells express themselves and regulating production of numerous substances including enzymes, hormones and neurotransmitters

Just one example of an important gene that vitamin D up-regulates is your ability to fight infections. It produces over 200 anti-microbial peptides, the most important of which is cathelicidin, a naturally occurring broad-spectrum antibiotic. Vitamin D can decrease your risk for common respiratory infections as well. At least five studies show an inverse association between lower respiratory tract infections and D levels. That is, the higher your vitamin D level, the lower your risk of contracting colds, flu, and other respiratory tract infections. A 2007 study suggests higher vitamin D status enhances your immunity to microbial infections. 

When produced in the skin or ingested, it is a vitamin or prehormone and essential for life. Just as cholesterol is metabolized into testosterone, precholesterol is turned into cholecalciferol (vitamin D), which is metabolized into a hormone 25(OH)D. In turn, this is metabolized in the kidneys or other organs into an even more potent hormone 1, 25(OH)2D.

Vitamin D is an essential part of the endocrine system. It controls several adrenal hormones, the growth of cells, the production of enzymes. 

Hormones have DNA receptor sites, while Vitamin D is a part of non- genomic coenzyme systems. In a way, vitamins A and D are both vitamins and hormones. Vitamin D is also produced in plants such as algae, as well as mushrooms (which are neither animals nor plants) exposed to ultraviolet-B (UVB) radiation.

Serum 25(OH)D levels should be in the 30 to 40 ng/ml (75-100 nmol/L) range for cancer prevention and optimal health. The only way to determine 25(OH)D levels is with a blood test which can be ordered through a physician or nutritionist. However, care should be exercised in the choice of a laboratory because the testing methods and quality of the tests may vary. In addition, since 25(OH)D and parathyroid hormone (PTH) are inversely correlated and have opposite effects on calcium in bones,  it would also be useful to have PTH levels measured.



Sunlight




Exposure to sunlight is an important source of vitamin D. Ultraviolet (UV) rays from sunlight trigger vitamin D synthesis in the skin. 

First, note that the 15 to 30 minutes per day generally applies to fair-skinned, thin, younger individuals, with the more of the body exposed, the better. Darker-skinned individuals may require several hours per day. For those unable to derive sufficient vitamin D from solar UVB, artificial UVB lamps are a viable option, as are vitamin D supplements.

The two viable options are artificial UVB and supplements. If visiting an indoor tanning salon, be sure to ask for the booth with the highest UVB (280-315 nm) to UVA (315-400 nm) ratio since only UVB produces vitamin D. UVA is useful in producing a browner tan.

Melanoma rates are rising as sun exposure and vitamin D status is decreasing dramatically. When you stay out of the sun entirely, you effectively avoid the system nature created to help prevent skin cancer naturally, because the key to unlocking this mechanism is vitamin D. Vitamin D is formed in your skin from exposure to sunlight. The vitamin D then goes directly to the genes in your skin where it helps prevent the types of abnormalities that ultraviolet light causes. When you avoid the sun entirely, or slather on sun block whenever you go out, your skin is not making any vitamin D, and you’re left without this built-in cancer protection. 

Dietary sources of vitamin D are generally insufficient to produce optimal serum 25-hydroxyvitamin D 25(OH)D since milk contains only 400 I.U. of vitamin D3 and 800 to 1000 I.U. per day are probably required. Fish oil with vitamin D can be consumed, but one should see whether and how much vitamin A is included. Vitamins A and D interact and you need the proper balance of vitamin A. Vitamin D is stored in the blood for a few weeks and in the fat for a few months. Vitamin D comes from two sources: food and sunlight. Some of the best food sources are mushrooms, liver, egg yolks, and fish.

Sun exposure benefits your health by stimulating your skin to produce vitamin D. Vitamin D is a hormone-like substance critical for the vast majority of your biological functions, including:

  • Cardiovascular health
  • Cognition
  • Sleep
  • Immunity
  • Metabolism
  • Bone health and strength
  • Digestion







Vitamin D is the superhero of nutrients, and the best way to get it is from appropriate sun exposure, which causes your skin to manufacture it. Vitamin D levels have been tied to cancer risk: the lower your levels, the higher your risk. Every cell and tissue in your body needs vitamin D to function properly. But it does more than just that. Vitamin D is different from other vitamins in that it influences your entire body. Receptors that respond to the vitamin have been found in almost every type of human cell, from your brain to your bones. This is why researchers are finding health benefits from vitamin D in virtually every area they look. For example, optimizing your vitamin D levels can help you to prevent as many as 16 different types of cancer including pancreatic, lung, breast, ovarian, prostate, and colon cancers. 







When you get your vitamin D from appropriate sun exposure, your body can self-regulate and reduce vitamin D production if you don't need it, which makes it very difficult to overdose on vitamin D from sun exposure.



D2 and D3

Supplemental vitamin D comes in two forms: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Recent studies have shown that vitamin D3 is a more potent form of vitamin D. Vitamin D2 has a shorter shelf life, and its metabolites bind with protein poorly, making it less effective. 

One unit of cod liver oil (containing vitamin D3) has been shown to be as effective as four units of Viosterol (a medicinal preparation of vitamin D2). 

Basically there are two types of oral vitamin D supplements. The natural ones are D3, and they contain the same vitamin D your body makes when exposed to sunshine. The synthetic ones are vitamin D2, which are sometimes called ergocalciferol. 

Once either form of the vitamin is in your body, it needs to be converted to a more active form. Vitamin D3 is converted 500 percent faster than vitamin D2. Interestingly, it was previously thought that the kidney exclusively performed this function, However, in 1998 Dr. Michael Hollick, the person who discovered activated vitamin D, showed that many other cells in your body can make this conversion, but they use it themselves, and it is only the kidney that makes enough to distribute to the rest of your body.

However, nearly all the prescription-based supplements contain synthetic vitamin D2, which was first produced in the 1920s through ultraviolet exposure of foods. The process was patented and licensed to drug companies for use in prescription vitamins. The vitamin D that is added to milk is not D3 but the inferior vitamin D2.






Hypercalcemia: Vitamin D Toxicity


When you take large amounts of vitamin D, your liver produces too much of a chemical called 25(OH)D.

When your 25(OH)D levels are too high, this can cause high levels of calcium to develop in your blood. High blood calcium is a condition called hypercalcemia.

The symptoms of hypercalcemia include:
  • feeling sick or being sick
  • poor appetite or loss of appetite
  • feeling very thirsty
  • passing urine often
  • constipation or diarrhea
  • abdominal pain
  • muscle weakness or pain
  • feeling confused
  • feeling tired

In some rare diseases, you may be at risk of hypercalcemia even if you have low vitamin D levels and haven’t taken much vitamin D. These diseases include primary hyperparathyroidism, sarcoidosis and a few other rare diseases.



Sunscreen

Sunscreen blocks your body’s production of vitamin D,which happens naturally when your skin is exposed to sunlight, by as much as 97.5 to 99.9 percent. 


Prevent Skin Damage

Ultraviolet light from the sun comes in two main wavelengths: UVA and UVB. UVB helps your skin produce vitamin D. UVA penetrates your skin more deeply and causes more free radical damage. UVA rays are constant during ALL hours of daylight, throughout the entire year, unlike UVB, which are low in morning and evening, and high at midday. 

Two non-toxic ingredients that scatter both UVB and the more damaging UVA rays are the natural minerals titanium dioxide and zinc oxide. 







What Makes Sunscreens Toxic? 

A study in the April 2004 Journal of Chromatography found that there was significant penetration into the skin of all sunscreen agents they studied and it goes straight into your blood stream. Scientists are not even sure whether sunscreen prevents against melanoma. They’ve suggested that sunscreen may prevent sunburn, but may fail to actually protect against cancer because most sunscreens only screen out UVB, which makes vitamin D, not the UVA that causes most of the damage. Some studies have even found a link between melanoma and the use of commercial sunscreen!

As you can see from the list below, compiled from the Environmental Working Group: Skin Deep Website, there are lots of potential dangers lurking in your sunscreens: 

Octinoxate (Octyl Methoxycinnamate) The most widely used sunscreen ingredient, known for its low potential to sensitize skin or act as a phototallergen. Estrogenic effects are noted in laboratory animals as well as disruption of thyroid hormone and brain signaling. Has been found to kill mouse cells even at low doses when exposed to sunlight! 

Oxybenzone (Benzophenone-3) Associated with photoallergic reactions. This chemical absorbs through your skin in significant amounts. It contaminates the bodies of 97% of Americans according to Centers for Disease Control research. Health concerns include hormone disruption and cancer.

Octisalate is a weak UVB absorber with a generally good safety profile among sunscreen ingredients. It is a penetration enhancer, which may increase the amount of other ingredients passing through skin. 

Avobenzone (Parsol 1789) Primarily a UVA-absorbing agent, sunlight causes this unstable ingredient to break down into unknown chemicals, especially in the presence of another active, Octinoxate. 

Octocrylene Produces oxygen radicals when exposed to UV light. 

Homosalate Research indicates it is a weak hormone disruptor, forms toxic metabolites, and can enhance the penetration of a toxic herbicide. 

Micronized Titanium Dioxide Sunscreens with micronized titanium dioxide may contain nanoparticles. Micronized TiO2 offers greater sun protection than conventional (larger) particles. These small particles do not penetrate skin but may be more toxic to living cells and the environment. Inhalation of powders and sprays is a concern. 

Micronized Zinc Oxide Same as Micronized Titanium Dioxide, above. 

Titanium Dioxide Appears safe for use on skin, due to low penetration but inhalation is a concern. 

Ensulizole (Phenylbenzimidazole Sulfonic Acid) Known to produce free radicals when exposed to sunlight, leading to damage of DNA, this UVB protector may have the potential to cause cancer. 

Nano Zinc Oxide offers greater sun protection than larger zinc particles. Comparatively little is known regarding potential health effects of nanoparticles. They do not penetrate healthy skin, and thus appear to pose a low health risk in lotions. Inhalation of powders and sprays is a concern. 

Nano Titanium Dioxide Same as Nano Zinc Oxide, above.

Zinc Oxide has a long history of use in sunscreen and other skin care products; little absorption and no adverse health effects are reported. 

Padimate O (Octyl Dimethyl PABA / PABA Ester) A derivative of the once-popular PABA sunscreen ingredient, research shows this chemical releases free radicals, damages DNA, has estrogenic activity, and causes allergic reactions in some people. 

Menthyl Anthranilate 1 study found that it produces damaging reactive oxygen species when exposed to sunlight. 

Mexoryl SX 2 hours of sunlight can degrade as much as 40% of this active ingredient. Low skin penetration. 

Methylene Bis-Benzotriazolyl TetramethylbutylphenolNot an approved active ingredient in the U.S. Few studies exist on this chemical. It is photostable and does not absorb through your skin. 

Sulisobenzone (Benzophenone-4) Can cause skin and eye irritation. Does not penetrate your skin to a large degree, but enhances the ability of other chemicals to penetrate. 

Benzophenone-2 Not approved for use in North American sunscreens. Concerns about hormone disruption.



Natural & Healthy Sources of SPF


10 Oils With Sun Protection Factor (SPF)



Fortunately, there are natural ways to protect yourself from sunburn that you can use instead of resorting to toxic sunscreens. Two non-toxic ingredients that scatter both UVB and the more damaging UVA rays are the natural minerals titanium dioxide and zinc oxide. The most obvious and safest option is to put on a long sleeved shirt, pants and a hat once you’ve reached your limit of sun exposure (you can tell you’ve had enough right when your skin turns the lightest shade of pink). 

Don't forget to hydrate when out in the sun.