|
medpundit |
||
 |
 |
|
Friday, August 24, 2007In addition, the label would also warn that "UV exposure from the sun increases the risk of skin cancer, premature skin aging and other skin damage. It is important to decrease UV exposure by limiting time in the sun, wearing protective clothing and using a sunscreen." Directions would tell people to reapply sunscreen "at least every 2 hours." The intent of the warning is to alert consumers that sunscreen is only a part of protecting yourself from sun exposure, Holman said. According to the FDA, the proposal has guidelines for testing that manufacturers need to do to support their claims. Under the rule, sunscreens could have a maximum SPF of 50+ unless test data shows that a higher number is warranted. In addition, the definition of SPF would change from "sun protection factor" to "sunburn protection factor." This change will prevent "the impression of solar invincibility and a false sense of security," according to the agency's proposal. The FDA will now require sunscreen labels to tell us how well they protect agains UVA radiation in addition to the UVB protection they already proclaim. Certainly, sunburns and frequent exposure to large amounts of sun are a risk factor for sun cancer. Sun screen is a necessity if, for example, you are spending the day at the beach or on the water, or shirtlessly shingling roofs. However, as always, all things in moderation. The sun and its UVB radiation is important in vitamin D production. This review article ($$$ required for full article) makes a very persuasive case of the importance of vitamin D to the human body: Although there is no consensus on optimal levels of 25-hydroxyvitamin D as measured in serum, vitamin D deficiency is defined by most experts as a 25-hydroxyvitamin D level of less than 20 ng per milliliter (50 nmol per liter)....a level of 25-hydroxyvitamin D of 21 to 29 ng per milliliter (52 to 72 nmol per liter) can be considered to indicate a relative insufficiency of vitamin D, and a level of 30 ng per milliliter or greater can be considered to indicate sufficient vitamin D. With the use of such definitions,it has been estimated that 1 billion people worldwide have vitamin D deficiency or insufficiency. According to several studies, 40 to 100% of U.S. and European elderly men and women still living in the community (not in nursing homes) are deficient in vitamin D. More than 50% of postmenopausal women taking medication for osteoporosis had suboptimal levels of 25-hydroxyvitamin D — below 30 ng per milliliter (75 nmol per liter). Children and young adults are also potentially at high risk for vitamin D deficiency. For example, 52% of Hispanic and black adolescents in a study in Boston and 48% of white preadolescent girls in a study in Maine had 25-hydroxyvitamin D levels below 20 ng per milliliter. In other studies, at the end of the winter, 42% of 15- to 49-year-old black girls and women throughout the United States had 25-hydroxyvitamin D levels below 20 ng per milliliter,25 and 32% of healthy students, physicians, and residents at a Boston hospital were found to be vitamin D–deficient, despite drinking a glass of milk and taking a multivitamin daily and eating salmon at least once a week. In Europe, where very few foods are fortified with vitamin D, children and adults would appear to be at especially high risk. People living near the equator who are exposed to sunlight without sun protection have robust levels of 25-hydroxyvitamin D — above 30 ng per milliliter.27,28 However, even in the sunniest areas, vitamin D deficiency is common when most of the skin is shielded from the sun. In studies in Saudi Arabia, the United Arab Emirates, Australia, Turkey, India, and Lebanon, 30 to 50% of children and adults had 25-hydroxyvitamin D levels under 20 ng per milliliter. Also at risk were pregnant and lactating women who were thought to be immune to vitamin D deficiency since they took a daily prenatal multivitamin containing 400 IU of vitamin D (70% took a prenatal vitamin, 90% ate fish, and 93% drank approximately 2.3 glasses of milk per day); 73% of the women and 80% of their infants were vitamin D–deficient (25-hydroxyvitamin D level, <20 ng per milliliter) at the time of birth. We always think of Vitamin D as being important for bone health, which it is, but it's also an important factor in muscle strength and performance, and it regulates cell growth (which could give it a role in the body's natural defenses against cancer). So how much sun exposure is enough? Sensible sun exposure can provide an adequate amount of vitamin D3, which is stored in body fat and released during the winter, when vitamin D3 cannot be produced. Exposure of arms and legs for 5 to 30 minutes (depending on time of day, season, latitude, and skin pigmentation) between the hours of 10 a.m. and 3 p.m. twice a week is often adequate.... ....exposure to a tanning bed for 30 to 50% of the time recommended for tanning (with sunscreen on the face) is an excellent means of treating and preventing vitamin D deficiency. If the sun is too scary, however, one may take a vitamin D supplement- but again, in moderation. It's possible to overdose on vitamin D. The author of the review article suggests 800-1000 IU a day. I'm not often persuaded by claims for vitamins, but after reading that review, I, too, thought vitamin D seemed the elixir of life. And I started taking a vitamin D tablet every day since I'm slaving away in my office between 10 and 3 every day. UPDATE: One of the comments challentes me to find a fatality from vitamin D overdose. Vitamin D intoxication causes renal failure and elevated calcium levels. Either of those can kill you. The good news is that it's reversible if the cause is recognized and the vitamin D supplements stopped. (See this case.) posted by Sydney on 8/24/2007 08:23:00 AM 7 comments 7 Comments:Does a Vitamin D tablet really replace sun exposure?
By Yes, as long as you don't have a problem with absorbing it.
So I should avoid the sun, but in doing so I put myself at risk so there's another thing I can do to fix that.
By
Vitamin D in tablet form may not be well absorbed by most people. Oil-based capsules seem to be much more effective at actually increasing 25-hydroxyvitamin D levels, according to William R. Davis, MD of the Heart Scan Blog.
By In researching our book "Avoiding Cancer One Day At A Time" I was shocked, not only that we were unable to find a study that would suggest the use of sunscreen might lower the risk of melanoma as commercials would suggest, but that we have not asked the question, what did our grandparents do? In 1935, before sunscreen was available, the risk of melanoma (responsible for 75 percent of skin cancer deaths) was one in 1200. It is now one in 84. Our grandparents insisted their children and grandchildren go outside daily, rain or shine for at least half an hour, but encouraged protective clothing, hats, and coming indoors during the peak hours to avoid burning. While we await more appropriate labeling of sunscreens, and even then, perhaps we should add in commonsense! Only, nobody makes money advertising commonsense...
By
How many people have overdosed on Vitamin D.
By Lifetime of antidepressants: diabetics need insulin their whole lives; ppl with thyroid disorders have to take their thyroid meds for a lifetime. same same same, no shame. |
|
