Too Little of a Good Thing
You've seen the commercials - the little lizard with a British accent who claims he can change your life (or at least the part influenced by car insurance) in just 15 minutes.
I don't know much about insurance - I'll leave that to talking reptiles. But I do know that 15 minutes is enough to change your life - in fact, it's enough to save it.
Researchers say that's all the time you need in the sun each day to get the vitamin D you need to stay healthy. And we're not just talking about avoiding the sniffles - those 15 minutes a day can protect you from cancer.
That's right, the sun can protect you from cancer. In recent years, researchers have noticed a trend: cancer rates are higher in areas of higher latitude, where sun exposure is more limited. Specifically, they've seen this tendency apply to cancer of the breast, colon and pancreas.
And now, new research suggests it's true for ovarian cancer as well: Scientists at the University of California San Diego analyzed data on ovarian cancer incidence in 175 countries. They factored in each country's latitude, UV radiation and atmospheric ozone levels, which affect UV transmission.
They found that ovarian cancer was more prevalent in higher latitudes; conversely, rates were lowest in areas with the highest UV radiation.
(This study didn't specifically link ovarian cancer with vitamin D levels. But we know that when the sun's UV radiation hits our skin, it triggers the production of vitamin D in the body. And reams of previous research have shown a link between blood vitamin D levels and cancer risk.)
But for many of us, getting that 15 minutes a day is problematic. Some experts say you have to expose half your skin to the sun during those 15 minutes to reap benefits. I'm all for year-round exercise and fresh air - but I'm also no fan of hypothermia. I can just imagine the looks I'd get from my New England neighbors if I ran around the yard in December with half my skin exposed.
And let's face it, life often gets in the way, no matter where you live: many people spend all the day light hours inside a building, with little to no opportunity to get out in the sun. Plus, pollution and ozone depletion have made it harder and harder for the sun's healing rays to get to us. And for anybody living north of the Mason Dixon line, it's impossible to get enough sun between the months of October and April due to the low angle winter sunlight. There's a whole host of factors conspiring to keep us from getting our vitamin D from the sun.
Vitamin D isn't present in foods, so our only alternative is supplements. Fortunately, they seem to work. One study found that people who took 400 IUs of vitamin D each day were half as likely to develop pancreatic cancer as people who didn't take any.
It also works to help improve calcium absorption in the bones. Taking vitamin D along with your calcium supplement ensures that all the good stuff is making a difference - and not just getting flushed out of your body - and down the toilet. Plus, studies have shown that vitamin D can help protect your joints from arthritis, and help prevent multiple sclerosis.
Despite all this research, most people are still seriously deficient in vitamin D. I recommend supplementation for just about everyone - the only contraindications are for people with kidney disease. Some people are afraid of getting too much, which can cause nausea, fatigue and kidney dysfunction. But you'd really have to go overboard to get there.
The FDA says the "upper tolerable limit" is 2,000 IUs a day, but some experts think you're fine up to 10,000 IUs a day. Point is, toxic levels are much higher than previously believed and way above what anyone is likely to ingest from supplements.
While the study I referred to above used a dose of 400 IUs a day, I usually recommend more - 1,000 to 2,000 IUs a day. Here's a good way to get some of it: A teaspoon of cod liver oil delivers a healthy 400 IU dose of vitamin D along with beneficial omega-3 fatty acids, which can protect your heart and your brain - while adding its own cancer fighting power. But not all cod liver oils are created equal: Most have less vitamin D and too much vitamin A. Stick with the widely available Carlson's brand and you'll get the right amounts of both. A couple of teaspoons a day can be enough for many of you if your vitamin D blood levels are adequate (above 30 nanograms per milliliter).
I still think it's a great idea to get outside for at least 15 minutes every day year-round: a brisk walk in almost any weather is great exercise and a good anecdote for winter cabin fever. But to be safe, back that up with a supplemental source of vitamin D. It will take way less than 15 minutes - and it may save your life.
