The importance of the sun

Sunlight glints through trees in October 2025. (Jasz Garrett / Juneau Independent)

By Murray Buttner

Well, it has begun. The sun has been getting lower in the sky since the solstice in June, but this week we moved into our dark half of the year. 

It is always a bit shocking how fast it happens. We are now losing five minutes of sun a day. And just as importantly, the sun's path across the sky is getting lower. In June the sun was 55 degrees above the horizon at noon. It is a little over 30 degrees above the horizon now, and it is heading down to where it will be just eight degrees above the horizon on the winter solstice in December.

Our latitude is not very high compared to most of Alaska, so theoretically we should have more sunlight than most of the state in the winter. But unfortunately, our skies are frequently overcast, and the proximity of our mountains, though spectacular, means that we are frequently in the shadow of the clouds and the mountains (especially downtown and in Douglas). Lastly, our magnificent rainforest is a deep green that absorbs, rather than reflects light.

We all know what a difference it makes when we have snow on the trees and so much more light is reflected. If you look at a map of the solar energy distribution around the world, Southeast Alaska is one of the least sunny areas on the planet. This has important implications for our health and wellness.  

Sunlight plays an enormous role in our health. The science on this is extremely interesting and not widely known. There is a fantastic new book that I highly recommend to everyone living here. It is called "In Defense of Sunlight" by Rowan Jacobsen. 

Amongst the many topics he covers is that sunlight provides much more to us than vitamin D. In fact, vitamin D is essentially a marker for sunlight rather than a replacement for sunlight. For the first two decades of this century, vitamin D was seen as a miracle supplement that could do just about anything. 

Unfortunately, numerous large studies have shown that our hopes for the benefits of taking supplemental vitamin D have not panned out. We need sunlight, not vitamin D pills. Sunlight is the miracle supplement.

So what can we do to make the best of our situation, our paucity of sunlight from September to March? We need to be proactive about getting what we can. 

How can we do this? First, we need to get out: Get outside when it is sunny; get out the road if you live downtown or in Douglas (or any other shady part of our city); get out of town and take a trip to somewhere sunny if you can. Second, if we work indoors, try to maximize natural and artificial light where we are working. Good full-spectrum light bulbs can provide many of the benefits of real sunlight. Third, consider getting a therapy light. These are high-intensity lights to use for 15-30 minutes in the morning. They really work and they are not very expensive.  

Being proactive about getting light will pay large dividends for both our physical and our emotional health until we get back to those long days of spring and summer.

• Murray Buttner is a doctor who lives in Juneau.