Sunbathing

Find Some Sunshine and Let It Shine On You!

Take a stroll through your local plant nursery and you’ll notice that plants come with labels indicating the amount of sun that they need to thrive. Planting outside of this recommended sunshine zone results in poor performance. Similar to plants, people also have a range of sunlight in which they thrive. Different people do best with different amounts of sun, so finding the right range of exposure for you is an important part of maintaining a healthy lifestyle.

 

Sunbathing was a favored American pastime before the connection between sun exposure, skin cancer, and premature aging was understood. Now we huddle in the shade, cover up, slather ourselves with sunscreen, and the only healthy tans we usually see are the ones someone purchased from a tanning salon. It is true that too much sun exposure, and especially sun burns, contribute to skin cancer. But the message to avoid the sun altogether may be misguided. Our increasing knowledge about vitamin D, the sun, and how they affect our immune system has us re-thinking the recommendation to avoid the sun completely.

Our ancestors were outdoors far more often than indoors. How could we have evolved and survived as a species if we were that vulnerable to something humans have been constantly exposed to for their entire existence? Like all living things, we need sunshine. Much as plants harness the sun’s rays through photosynthesis, our bodies use the UVB radiation in sunshine to stimulate increased production of vitamin D. Vitamin D is needed to build bones, quell inflammation, bolster the immune system, and protect against disease. 

Children who do not get enough sun, do not develop healthy bones and older people who have too little are more prone to falls and fractures.  People who live farther away from the equator (and are exposed to less sun) have higher risks of diseases — including heart disease, high blood pressure, type I diabetes, multiple sclerosis, depression, asthma, osteoporosis, cancer, and auto-immune disease. Most people have heard of the studies that connect sun exposure to skin cancer. But there are many studies that suggest sun exposure (and maximizing vitamin D levels) plays a role in decreasing risks of at least 16 different types of cancer including lung, pancreatic, breast, ovarian, prostate, and colon cancers.

Without question sun exposure and the vitamin D we make when in the sun is vital to health. But how much do we need?  Medical experts vary on the recommendations and, depending on someone’s medical history and health status, individual needs may vary. Some experts recommend blood serum levels as high as 75 ng/ml. If we use that level as a guide, three out of four Americans are deficient. The Institute of Health recommends blood serum levels at 40 ng/ml, the amount that meets the needs of most people. Using either value, many Americans are deficient in vitamin D.

Deficiencies are not only common in adults, they are common in children as well. Two recent studies published in the Journal of Pediatrics estimate that 70% of American kids aren’t getting enough vitamin D and infants are particularly vulnerable. Infants that are born from vitamin D deficient mothers and remain vitamin D deficient for the first several months after birth have a greater risk of developing obesity and chronic diseases later in life.

Although called a vitamin, it is not. Vitamin D is in a class by itself, behaving more like a hormone. It is made in the skin, gets into your bloodstream and then goes into the liver and the kidneys where it becomes activated as a key steroid hormone called Calcitriol. It then travels throughout the body to the intestines, bones, and other tissues — effecting the expression of a myriad of genes and a multitude of metabolic pathways. Vitamin D’s active form interacts with almost every cell in the body directly or indirectly. It has a dramatic impact on the health and function of your cells. It reduces cellular growth and improves cell differentiation (which puts cells into an anti-cancer state). But what’s even more fascinating is how vitamin D regulates and controls genes. Vitamin D hooks onto cells and then sends messages to our genes. That’s how vitamin D controls so many different functions like reducing inflammation, boosting mood, activating the immune system, easing muscle aches and fibromyalgia, and building bones.

In a study of Finnish soldiers, those with vitamin D levels higher than 40 ng/ml had fewer respiratory infections than those with lower levels. In another trial involving school girls, researchers found that supplementation with 1200 IU/d of vitamin D3 reduced influenza.

 

Eighty to 100% of the vitamin D we need comes from the sun. The sun exposure that makes our skin a bit red (called 1 minimum erythemal dose) produces the equivalent of 10,000 to 25,000 international units (IU) of vitamin D in our bodies. The problem is that most of us aren’t exposed to enough sunlight throughout the year to maintain healthy vitamin D levels.

One reason that we don’t get enough sun is the overuse of sunscreen. While sun-blocks help protect against burning and skin cancer — they block a whopping 97% of your body’s vitamin D production. Other known factors that affect vitamin D production include body weight, body fat percentage, age, skin pigment, the latitude of where you live, individual reactions to sun exposure, and our overall health. The average 70-year-old person creates only 25 percent of the vitamin D that a 20 year-old does. Dark skinned people need two to three times more sun exposure than light skinned people to maintain their
vitamin D levels. As a general rule, older people need more vitamin D than younger people, large people need more than small people, overweight people need more than thin people, people living in the north need more than people living in the south, dark-skinned people need more than fair-skinned people, winter people need more than summer people, sun-phobes need more than sun worshipers, and ill people may need more than almost anybody.

For healthy people, moderate sun exposure (2 to 4 times a week for 15 to 30 minutes) is not a problem. Just as important as not avoiding the sun all together, it is important to not just bake away. Rather follow healthy sunbathing tips (see our list).  Because there are so many variables to consider, it is always a good idea to talk with your medical provider before you embark on more sun-time. Depending on your unique medical history, your primary care physician may not want you exposed to more sun. If that is true, talk with your provider about supplementing with vitamin D.

While you do get some vitamin D from food sources, you can’t get enough from your diet. Fortified vitamin D foods such as milk and cereals provide the vitamin D2 form which is much less well utilized by the body. Dietary sources that provide vitamin D3 include eggs, salmon, tuna, mackerel and sardines, all of which are also good sources of calcium, iodine, and vitamin E which work together with Vitamin D.

If you do choose to supplement, look for one that provides D3 (the active form of cholecalciferol) rather than D2 (ergocalciferol). Vitamin D3 is better absorbed and better utilized in our bodies. Research indicates that it is probably a good idea to take a vitamin D supplement that contains vitamin K2 as well. While vitamin D is vital for the absorption and transport of calcium in the blood stream, vitamin K2 works with vitamin D to direct how and where the calcium is used. Vitamin K is synthesized in our gut by bacteria and because of our modern day diets, most of us are probably low in vitamin K as well. If you are on blood thinners, do not take any vitamin K without talking to your physician first (vitamin K is a potent de-coagulator and thins blood as well). Lastly, research shows that taking your vitamin D supplement with a meal that has some healthy fat sources, like avocado, olives, nuts, etc. increases absorption of the vitamin D.

The benefits we receive from the sun have focused primarily on its ability to stimulate vitamin D production, but there may be other benefits we get from the sun that are not yet well understood. Even if you supplement with vitamin D, it’s still a good idea to get some sunshine as well. If your medical provider gives you an okay, follow the healthy sunbathing tips on the following page to help you sunbath safely. 

Healthy Sun-Bathing Tips!

  • Avoid getting burned. Repeated sunburns, especially in children and very fair-skinned people, are linked to skin cancers.  Most people should be okay with regular, small amounts of sun exposure.
  • Prepare your skin and buildup tolerance gradually. Start early in the year (spring), or early in the morning before the sun is strongest and slowly build up the amount of time you spend in the sun. After building a tolerance, aim for short exposures (15 to 30 minutes) either in the early part of the day, or, if your vitmain D is low and you do not burn easily, at mid-day. Middle of the day exposure maximizes vitamin D production. Significant vitamin D production occurs when your shadow is shorter than you are. If you have had skin cancer, ask your provider about modifying these suggestions.
  • Aim for 15 to 30 minutes of unprotected sun exposure two to four times a week. To reap the maximum benefits, expose as much of your skin as you can, not just your arms and face.
  • After your 15 to 30 minutes of sun or if your skin begins to redden, protect your skin immediately. Wear a hat and light colored clothing that blocks the sun and keeps you cool. Apply sunscreens as needed. Remember that even weak sunscreens block the ability of your skin to manufacture vitamin D, so once you have applied it, you will not be making vitamin D.
  • Boost your “internal sunscreen” by consuming antioxidant foods and beneficial fats. These foods strengthen skin cells, helping to protect them from sun damage. On a regular basis eating several servings of vegetables and fruits such as blueberries, raspberries, goji berries, and pomegranates, and supplementing with green powdered mixes (wheat grass, barley grass, seaweed powders, etc.) and fish oils are great options when going into the sun.
  • Talk with your primary care physician about whether you should have your vitamin D blood levels checked and whether you should take a vitamin D supplement. The current normal range for vitamin D is 20 to 55 ng/ml, however your medical provider may want you to achieve higher levels closer to 50 to 75 ng/ml. At your next visit, talk with your provider about what is best for you.

This article written by Vicki Pepper M.S., R.D. for Kaiser Permanente Positive Choice Wellness Center. ©2016 Kaiser Permanente. All rights reserved SCPMG Positive Choice Integrative Wellness Center, San Dieg

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