Here’s what you need to know to enjoy the summer months, get the Vitamin D your body needs, and stay safe in the sun.

Here Comes the Sun

Vitamin D is arguably the easiest vitamin to take. Your body produces Vitamin D by itself, with a little help from the sun’s ultraviolet B (UVB) rays. Since the body can store inactive Vitamin D, you can ‘stock up’ in summer for the gray winter months to come.

What does Vitamin D do?

A better question might be: What doesn’t it do? Vitamin D plays a big role in promoting and maintaining your health, inside and out – strengthening bones, helping muscle performance, boosting your immune system, improving mood, and facilitating calcium and phosphorus absorption. Sufficient levels of Vitamin D are also key to protecting against and treating cancer, diabetes, heart disease, hypertension, osteoporosis, multiple sclerosis, Alzheimer’s disease, and more.
Since Vitamin D plays an important role in regulating calcium and phosphorus, it’s not so surprising that kidney patients often experience low levels of Vitamin D. Depending on the nature of your kidney disease and health circumstances, your doctor can monitor your Vitamin D levels and address any deficiencies according to your health needs.

How much Vitamin D do I need and how do I get it?

Sunlight is the best source of Vitamin D, and you don’t need to tan or burn your skin to get it. In fact, in only around half the time it takes for your skin to begin to burn, your body can produce 10,000 – 25,000 IU of vitamin D – covering your daily allowance and then some. Since Vitamin D is fat-soluble, whatever your body doesn’t use isn’t easily eliminated, so your body can access and activate Vitamin D from the surplus.
You can’t get enough Vitamin D from diet alone, unless you exist solely on fatty fish, beef liver and egg yolks. (Yikes!) Even then, you probably wouldn’t get enough vitamin D. The recommended daily dosage varies depending on the source, but falls somewhere between 600 IU – 5000 IU/day. A supplement can fill the gap, but be sure to discuss it with your doctor. More on that later . . .

So I can get Vitamin D anywhere, any time the sun’s out?

Not exactly. Anything that interferes with UVB rays will make it harder for you to make Vitamin D. Your skin also makes a difference in how much and how quickly your body produces Vitamin D. A little bit about how it works here . . .

A Little Latitude, Please

When the sun is at too much of an angle to the Earth, the atmosphere blocks the UVB rays in sunlight. If you live close to the equator, you should have no problem producing vitamin D all year round. But the further north you go, it may be impossible to make Vitamin D during the winter months. In Florida, for example, your body can produce vitamin D most of the year, while in Boston, you’re not going to get any vitamin D from the sun from November through March. That might be the right time to head for the hills. The sun is more intense on top of a mountain. The higher up you are, the more vitamin D your body can make.

I Want My UVB

On cloudy days, fewer UVB rays reach your skin so your skin makes less vitamin D. If the air is polluted, it either soaks up UVB rays or reflects them back into space. If you live somewhere where there is lots of pollution, your skin makes less vitamin D. All sunscreens block UVB rays, as does glass. Sitting in a sunny room or driving with the windows up will prevent your body from producing Vitamin D.

It’s All Skin Deep

To get enough Vitamin D from the sun, you need to expose your skin for about half the time it takes for you to burn. Paler skin burns faster than dark skin, so it can only take 15 minutes to get a daily dose of Vitamin D. Darker skins, which have more melanin, allow fewer UVB rays into the skin. If you’re dark skinned, you’ll need more time in the sun to get the same amount of Vitamin D as your paler pals – up to an hour, even. Plus, the more skin you expose (your back vs. your hands), the more vitamin D you’ll produce. Older skin has a harder time producing vitamin D, so you need to adjust for your age as well.

What’s That Smell?

Showering after sunbathing reduces vitamin D intake. Yep, you read that right. Vitamin D is formed on your skin and needs time before it’s absorbed into your skin and your bloodstream. Washing after sunbathing, especially with soap, should be postponed . . . wait for it . . . up to 48 hours! But even four to six hours would be great if you can swing it . . . without losing any friends!

How can I tell if it’s a good time to get some Vitamin D?

There are two foolproof ways to tell when the conditions right for your body to form vitamin D.

Your Shadow Knows
It’s all about the angles again. On a sunny day, go outside and look at your shadow. If your shadow is as long as you are tall, or longer, your body can’t form vitamin D. If your shadow is shorter, now’s your chance to get some vitamin D. Early and late in the day will be less intense and you’re less likely to absorb much in the way of UVB rays.

The UV Index
The UV index indicates the radiation intensity of the sun on a scale of 0 to 11. Weather websites and apps include the daily local UV index in their forecasts so people can protect their skin on high-intensity days. A good rule of thumb is that the UV index needs to be higher than 3 for the sun to provide enough UVB rays for vitamin D formation.

What about protecting my skin?

Exposing your skin to the sun is healthy in moderation, but overexposure can increase your risk of skin cancer. If you’re soaking up the sun to get your Vitamin D, make sure you have some shade, clothing, a hat and/or sunscreen handy to avoid getting too much sun. All sunscreens are not created equal, however. To find a healthy sunscreen that also blocks both UVA and AVB light, check out the annual EWG reviews.

Can a Vitamin D supplement help?

For many of us, it’s hard to get enough sun exposure to keep our stores of Vitamin D stocked. And some people with kidney failure can’t make Vitamin D at all. Taking a supplement can give you the vitamin D your body needs. Speak to your doctor and get their recommendation based on your circumstances. There is such a thing as Vitamin D toxicity, but that’s hard to achieve – you’d have to take 40,000 IU /day for at least a couple of months.

If you’re considering a supplement, make sure you’re getting Vitamin D3 – not Vitamin D2. Vitamin D3 is what your body produces in response to sun exposure, and it’s what you’ll see on most shelves in the U.S. A note for vegetarians and vegans: Vitamin D3 supplements aren’t vegetarian, in which case, Vitamin D2 can be an alternative, or you can opt for more controlled sun exposure.

Now get outside, fire up the grill, lay out that beach blanket, and get your D on!