UNDEREXPOSED: THE SUNSCREEN AND VITAMIN D CONNECTION

It’s been drilled into our heads that when you go outside, you need to be protected from the damaging rays of the sun.

Too much sun exposure contributes to the formation of wrinkles and dark pigmentation in the skin, both of which can be unattractive signs of aging. So we liberally slather on the sunblock, which should make your dermatologist happy, right?

Well, before you opt for the Costco-sized jug of SPF 100, you should know that your well-intentioned efforts could be putting you at risk for vitamin D deficiency.

Sunscreens block ultraviolet B (UVB) rays from the sun, which is exactly what it was designed to do. But the UVB rays are just what your body needs to manufacture vitamin D. We need adequate amounts of vitamin D to help with the absorption of calcium and phosphorus for proper bone mineralization along with mood stabilization and immune function.

There are around 3,000 genes in the human body that are affected by vitamin D. The body has vitamin D receptors throughout it ready to uptake this nutrient that protects against a myriad of conditions, including diabetes, stroke, heart attacks, macular degeneration, and autoimmune diseases.

Surprisingly, vitamin D deficiency is a recognized pandemic, despite efforts to fortify the food supply with vitamin D, and for some, ample time to take advantage of the manufacturing qualities of the sun. With more than half the American population at risk for vitamin D deficiency, this problem is expected to perpetuate while we still live by the notion that maximum coverage from the sun is best.

Adding to the problem is the misuse of and lack of understanding of how sunscreens work. The higher the SPF (sun protection factor), the better protection – theoretically. But according to the Environmental Working Group, lotions with SPF 50 or higher tend to have a poor balance of protective chemicals. While these products are blocking the benefits of UVB penetration, they are not as good at blocking UVA rays, which penetrate deeper into the skin and suppress the immune system, ignite free radical formation and increase the risk of developing melanoma.

So you might be cutting down the chance of developing a sunburn, but underneath the surface, it’s a health gamble. Do you sacrifice the benefits of the UVBs while there’s still a chance of letting in the more harmful UVAs?

On a side note, you really have to watch out for the extra chemicals in high-SPF products, which require higher concentrations of ingredients that can cause tissue damage and disrupt hormones when they penetrate the skin. If used correctly, most people will get adequate protection from sunburns with sunscreens with SPF values from 30-50.

How long do you linger?

So how do you get the right amount of sun exposure in the safest way possible?

A little dab will not do in this instance. Slight exposure to the face and hands is typically not enough to produce sufficient amounts of vitamin D. To optimize vitamin D production you need to expose large portions of skin, like bare arms or legs, and it needs to be more than just a few minutes.

Aim for 10-20 minutes as your starting point and adjust for your skin color. You need just enough sun exposure for your skin to turn the lightest shade of pink. So the paler your skin the less time you need in the sun, and the darker your skin the longer you may need. Any longer than is necessary just leaves you open for skin damage. You’re not tricking your body into making more vitamin D beyond your needs by staying out longer.

A word of caution about the more fragile skin on the face

This area is at greater risk of photo damage and premature wrinkling from sun exposure. Since we’ve already established that the face is not a large enough surface area for optimal vitamin D production, feel free to don a broad-brimmed hat, sunglasses, and a safe sunscreen.

Best time of day to catch some rays

We’ve been warned to avoid the sun between the hottest parts of the day. Peak intensity, when UV light is the strongest, is usually from 10 am to 3 pm (standard time) or 11 am to 4 pm (daylight savings time). While this is good for avoiding sunburn and other heat-related health hazards, it’s during this time of day that you’ll optimize vitamin D production.

You want to be soaking up the sun as near to solar noon as possible (if accounting for daylight savings time, “noon” can be pushed to 1 pm). During this time, UVB rays are at their highest (they taper off in the morning and evening). During the UVB-intense period of 10 am to 2 pm, you’ll need the least sun exposure to max out your vitamin D production. And since you don’t need a lot of time, you’ll minimize your risk of skin damage because the UVA rays are pretty constant during all daylight hours, and you do want to limit your exposure to those rays.

Sorry, nude sunbathers – the all day, all over uni-tan is not working in your favor.

Can’t let the sunshine in?

We understand that not everyone has the pleasure of living in sunny Southern California – our sincere apologies – and gets to take advantage of well over 200 glorious days of sunshine per year. So during times of cloudy skies, cold weather or illness/injury that has you cooped up inside all day, make sure you’re taking a qualityvitamin D3 supplement.