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A Happy Light Might Be Your Best Friend During Dark Days with MS

Many people with MS may be struggling at this time of year. It could be due to external influences. Weather can be extreme and keep us indoors. This may lead to sedentary living or make us feel glum without access to sunlight and fresh air.

Seasonal struggles

It’s the beginning of flu season as well. That means we might also be stuck indoors under self-quarantine. Let’s face it, even if we get the flu vaccine, many in our community don’t, and that puts us at risk.

Finally, the stress of the holidays, as well as the post-holiday slump, can trigger pseudo-exacerbations, full-blown relapses, and more “normal” problems like seasonal depression, economic anxiety, grief over lost loved ones, and relationship troubles.

Multiple sclerosis and vitamin D

While there’s no simple solution for these problems, there are small efforts we can make to rise above the pain, stress, and doldrums of December. One of them is to reconsider our vitamin D intake.

Observational studies show that a deficiency in vitamin D is a modifiable risk factor for MS. Any deficiency you might have should be treated.

The benefits of vitamin D

Vitamin D is generally important for absorbing calcium via the stomach and for assisting in the function of calcium throughout the body. It’s also a critical partner in the body’s regulation of the immune and neuromuscular systems.

This explains why vitamin D levels should be kept within a normal range for those with MS. So much of our disease course depends on the stability of both of these systems.

Vitamin D deficiencies

Also worth mentioning: stable vitamin D levels are important for mood regulation. Deficiencies in vitamin D are linked to increases in winter depression (SAD).

Our bodies generate vitamin D, but only after sufficient exposure to sunlight. This is a problem for people who live in northern climates where natural sunlight is dim. Ironically, it’s also a problem for people in hot, sunny climates, where living takes place mostly indoors.

One popular way to rectify this situation is through dietary consumption of foods high in vitamin D or via vitamin D supplements.

What is a happy light?

The other way is to simply expose yourself to more natural light. But that can be hard to do when the weather is difficult or you can’t leave the home due to mobility issues. That’s where a “happy light” can come in handy.

A “happy light” references a light therapy device used to treat seasonal depression (or seasonal affective disorder, SAD). It’s composed of full-spectrum light that measures in at 10,000 lux. This amount mimics the measure of light one might experience when strolling outside on a sunny day.

Happy lights come in all shapes and sizes. Some look like plain white smartphones, while others look like lightboxes or have distinct cylindrical or round shapes. You can even find travel-sized happy lights. Some can also be plugged into the USB on your laptop.

How to use a happy light

Using a happy light is fairly simple.* Turn it on and sit within 20 to 24 inches of it for about 20 minutes a day. That’s it. You don’t need to (and shouldn’t) look directly at it. The benefit comes from light exposure received by photoreceptors in both the eyes and the skin. Some lamps have high-bright and low-bright settings. If the high setting is too bright, opt for the low setting.

Some people may experience a slight headache while using it for the first few times; that’s normal and will fade in short order. Over time, the happy light user will usually notice a couple of benefits: a drop in daytime fatigue (happy lights stimulate the pineal gland and slow down melatonin production which can leave us feeling sleepy) and an elevation in daytime mood.

Happy light benefits

However, the best benefit comes in something less obvious but no less important to the well being of anyone with MS: stable levels of vitamin D. When you have a normal amount of vitamin D in your bloodstream, the result is better function for both the immune and musculoskeletal systems. That, in turn, can lead to fewer relapses or exacerbations, less pain, and more energy during the day.

If you’re interested in participating in clinical trials phototherapy for treating MS symptoms, check out this Boston-based research study: Light Therapy as Treatment for Fatigue in Multiple Sclerosis. They are recruiting participants with relapsing-remitting MS.

What about vitamin D supplements?

These are enormously popular among people with MS, and for good reason: a lot of research suggests that higher vitamin D levels can correlate to fewer relapses and a slower progression of the disease. Yet, other recent research suggests vitamin D isn’t quite a wonder drug and may lead to adverse side effects when taken in mega doses. This is due to an unhealthy overload of calcium in the bloodstream.

Therein lies the problem: there’s no real consensus on how much vitamin D to take, or what defines vitamin D deficiency even in healthy people, or whether age is also a factor in the use of vitamin D to ward off disability. Too much vitamin D can lead to adverse effects such as nausea, vomiting, weakness, frequent urination, kidney stones, and exacerbation of bone problems.

Natural vitamin D

If you want to ensure you have adequate vitamin D, and that you are receiving safe amounts, there are two ways to do so: either by way of diet or light therapy.

Foods that are high in vitamin D include fortified products (milk, cereal, orange juice), egg yolks, and fatty cold-water fish.

But even easier is natural sunlight, which can be had by enjoying a 20-minute stroll (or roll) in the morning, even on an overcast day. Or, in inclement weather, a “happy light” with your morning coffee can do the trick.

*Please note that people with bipolar disorder should avoid light therapy of any kind except when guided by their psychiatrist, as light therapy can set off a manic period.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.


  • TK Sellman moderator author
    12 months ago

    Thanks for your comment, Kristin. You’re right, some research does suggest a connection between vitamin D and muscle strength/performance.

    As for spectral output, natural sunlight can run anywhere between 5 and 120,000 lux depending on time of day and cloud cover.
    Typical range is between 32,000 and 100,000 lux.

    I wouldn’t be concerned about finding adequate lux in a phototherapy device. You can find a good assortment of light therapy gadgets that offer 100,000 lux, and medical research supports that measure as being phototherapeutic.

    I have used 100,000 lux light therapy devices for years now (I live in Seattle, where it can be pretty dim for at least half the year) and I have had a great experience with them, so much so that I give them away as gifts!

    But key is the 100,000 lux output. Anything less isn’t going to be helpful. Choosing one with two settings is also worthwhile; I generally opt for the slightly less bright illumination because the ultrabright one gives me headaches.

  • Kristin
    12 months ago

    Hi, thanks for your reply. Thanks also for the information about lux. My question was actually about wavelength (color), not intensity (amount). The solar spectrum ranges from IR (wavelengths that make you hot) to UV (wavelengths that give you sunburn or, at shorter wavelengths, melanoma). There is a mix of wavelengths that triggers vitamin D production in the human body, so wavelength matters. I discovered this by accident when I noticed that getting sun at the end of the day didn’t give me the positive results that sun in the early afternoon did – at low angles, the sunlight passes through a greater amount of atmosphere than at high angles, and some crucial wavelengths get absorbed. So, “full-spectrum” bulbs may mimic the sun effectively for treatment of SAD but not necessarily for vitamin D production. I just haven’t dug into the research to find out specifics. I definitely want to do that before shelling out 500 bucks for a lightbox. I’d welcome any information you have to offer unless topic. Thanks a bunch!

  • TK Sellman moderator author
    12 months ago

    The good news is you can get a decent lightbox for less than 50 bucks. Mine was around $30. No need to shell out $500.

    Here’s some info about shopping for one from Mayo Clinic:

    Also, as for color spectrum, I may be wrong, but full spectrum does the best job of replicating the light from the sun, so color temperature is probably not something you need to worry about.

    I’ve never seen anything that suggests you only seek out a single color temperature to support vitamin D production, but I have seen cautions against isolating one type of light over another, as we need all of them for different reasons.

    Yes, color temperature changes over the course of the day, but our bodies are naturally attuned (entrained) to those changes thanks to our circadian rhythms.

    Keep in mind: lightboxes are meant to be used during the first half of the day.

    Also, there are other factors, such as where you live and your ethnicity, to keep in mind. Different colors of skin may respond to different color temperatures during vitamin D synthesis.

    Good luck!

  • Kristin
    12 months ago

    Vitamin D levels are about more than just mood or MS risk. If I get 20 minutes of sun, my muscles are stronger and more responsive the next day. I’m also less spastic. It’s kind of like day two of a steroid regime without the other nastiness. I first noticed it about three years ago – now I make a point of getting my outside time as soon the weather is warm enough. Been considering a lightbox but I’m skeptical that the spectral output is really a full match for the solar spectrum.

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