I'm really trying to understand what exactly Iodine does in terms of the sun-protection factor reported here, quite a few folks have posted that they no longer burn:) Hopefully you all will be able to make some connections here, I'm not sure that I have although I wanted to go ahead and post, maybe we can all figure this out together:) I still don't have a clue as to why people aren't getting burned... Iodine is vital for healthy skin and the ability to sweat...but WHY no burning??


http://www.helpmythyroid.com/iodine.htm


"20% of all Iodine in the human body is stored in the skin, specifically in the sweat glands. Lack of iodine in the sweat glands manifests as dry skin with a decreased ability to sweat."





Not only do we excrete iodine in our sweat, we can put ourselves in an iodine-deficient state through sweating. Athletes should be sipping Lugol's cocktails, not gatorade:)


http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=114...


Electrolyte loss in sweat and iodine deficiency in a hot environment.

"The authors studied electrolyte loss from profuse sweating in soccer-team players and evaluated the relationship between this source of iodine loss and iodine deficiency. Thirteen male soccer-team players and 100 sedentary students from the same high school were evaluated for 8 d, during which the players were training. The authors analyzed 208 sweat samples to determine losses of iodine, sodium, potassium, and calcium in sweat. Excretion of urinary electrolytes by the subjects was also measured. The mean losses of iodine, sodium, potassium, and calcium in sweat following a 1-hr game were 52 microg, 1,896 mg, 248 mg, and 20 mg, respectively; the ratios of sweat loss to urinary daily loss of the four electrolytes were 0.75, 0.2, 1.88, and 0.92, respectively. Urinary iodine was significantly (p < .02) lower than the normal level of 50 microg/gm creatinine in 38.5% of the soccer players, compared with 2% of the sedentary students. Forty-six percent of the players had Grade I goiter, compared with a mere 1% of the sedentary students (p < .01). The results of the study suggest that loss of iodine through profuse sweating may lead to iodine deficiency, and loss of electrolytes through sweating may have a dietary significance for heat-stressed individuals or for individuals who perform heavy workloads."

SWEAT AND SEBUM ~ THE ACID MANTLE....


http://www.smartskincare.com/skinbiology/sebum.html


"Sebum is an oily secretion produced by sebacious glands, tiny ducts adjacent to hair follicles. Sebum is secreted into the follicle, from which it spreads over the hair and skin. The main role of sebum is to waterproof the skin and hair. Both excess and lack of sebum are undesirable. Excess sebum is associated with oily skin and acne. It is particularly common in adolescents as the increased levels of sex hormones stimulate sebum production. Lack of sebum, which is common in middle and older age, leads to skin dryness and accelerates wrinkle formation.

Sweat is a salty, watery solution produced by sweat glands, numerous microscopic channels opening onto the skin surface. As sebum and sweat mix up on the skin surface, they form a protective layer often referred to as the acid mantle . Acid mantle has a particular level of acidity characterized by pH from about 4 to 5.5. A pH of 7 is considered neutral, above 7 is alkaline, and below is acidic. The pH of acid in the human stomach, for example, is usually from 1 to 2, which is highly acidic. The skin, on the other hand, is mildly acidic. In addition to helping protect skin from "the elements" (such as wind or pollutants), acid mantle also inhibits the growth of harmful bacteria and fungi. If acid mantle is disrupted or loses its acidity, the skin becomes more prone to damage and infection. The loss of acid mantle is one of the side-effects of washing the skin with soaps or detergents of moderate or high strength."

~So, when we iodine-sufficient ones are out sweating in the sun, our iodine-laden, salty sweat is mixing with our oily sebum. OIL & WATER! WE'RE MANUFACTURING OUR OWN VERSION OF THAT 60's FAVE, IODINE & BABY OIL! Do ya think? am i whacked? :)

Grz suggested a synergistic relationship between vitamin D & iodine some time ago. I'd love to see this idea expounded upon....when we get sun, the skin makes Vitamin D:) In fact....


http://www.pbs.org/wgbh/evolution/library/07/3/text_pop/l_073_04.html


"As far back as the 1960s, the biochemist W. Farnsworth Loomis had suggested that skin color is determined by the body's need for vitamin D. The vitamin helps the body absorb calcium and deposit it in bones, an essential function, particularly in fast-growing embryos. (The need for vitamin D during pregnancy may explain why women around the globe tend to have lighter skin than men.) Unlike folate, vitamin D depends on ultraviolet light for its production in the body. Loomis believed that people who live in the north, where daylight is weakest, evolved fair skin to help absorb more ultraviolet light and that people in the tropics evolved dark skin to block the light, keeping the body from overdosing on vitamin D, which can be toxic at high concentrations."

more on Vitamin D:


http://www.the-scientist.com/news/display/44290/


"Vitamin D generated by sunlight may help protect the skin from cellular damage, including damage caused by sunlight itself, suggests a new study published in this week's Nature Immunology. The researchers found that dendritic cells can convert vitamin D3 -- generated under the skin by sunlight -- into its active hormonal form, and induce T cells to migrate to the skin."

"It's a new action for a chemical we've known to be present for a long time," said Clay Cockerell, a dermatologist at the University of Texas Southwestern Medical Center at Dallas, who was not involved in the study. "We may eventually find that [the T cell response] is protective in some way against skin cancer."


http://www.sciencenews.org/articles/20041016/bob9.asp


"A few minutes of sun exposure on a summer day can generate huge quantities of vitamin D in a person's body. A cholesterol-like substance in the skin absorbs ultraviolet (UV) energy and creates vitamin D. Then, a cascade of chemical reactions turns vitamin D into a surprisingly versatile hormone-one that has long been recognized to help the body absorb calcium from the diet to build strong bones. Recent work, however, indicates that vitamin D also bolsters muscle strength, insulin action, immune health, and the body's natural defenses against cancer."

~ a cholesterol-like substance? What might that be? Sebum... ? The same sebum that mixes with our iodin-ey sweat?

& I wonder about the difference in vitamin D supplements/sunshine....

Go ahead, get your





just don't forget your





Oh! BTW, an interesting link on the benefits of nekkid sunbathing:)


http://www.healself.org/sun.html


:)