Vitamin D for SAD

New evidence from a small study suggests that vitamin D supplements may improve symptoms of seasonal affective disorder (SAD), a pattern of depression related to changes in seasons and a lack of exposure to sunlight.

SAD usually occurs during the winter months and may cause headaches, irritability and a low energy level. It is unclear exactly what causes SAD, although disruptions in the circadian rhythm and abnormal levels of melatonin, serotonin and vitamin D have all been suggested as potential contributors. 

During the winter months, many people are exposed to less sunlight, and sunlight helps the body make vitamin D3. Therefore, some researchers have suggested that vitamin D deficiency may play a role in SAD.

The study, published in the journal, Applied Nursing Research, included nine women who had borderline-low serum vitamin D levels (less than 40 nanograms per milliliter of blood) during the winter months. Six of these women completed questionnaires about their SAD symptoms before and after supplementation with 5,000 international units of vitamin D3 daily.

The researchers found that vitamin D supplementation was linked to an increase in serum vitamin D levels by an average of 27 nanograms per milliliter of blood and a significant improvement in SAD symptoms.

"This pilot study provides evidence to suggest that women who suffer from seasonal depressive symptoms may benefit from vitamin D3 supplementation if serum vitamin D levels are low," the authors concluded.

Although these early results are promising, this study is limited by its small sample size.

For more information about vitamin D, please visit Natural Standard’s Foods, Herbs & Supplements database.

Comments

[Jan]

It is really interesting that vitamin D may improve symptoms of seasonal affective disorder (SAD). I wonder if it would help depressive symptoms that were not related to SAD, regardless of the level of sunlight exposure? I also wonder if SAD occurs even in patients with normal vitamin D levels, or if it only occurs in people with borderline or low levels. This study only involved women with borderline-low levels.

[Phillip]

I was aware that lack of sunlight exposure could lead to decreased levels of vitamin D. I was not aware that low vitamin D levels were associated with seasonal affective disorder. Does anyone know why low levels of vitamin D can result in patterns of depression, such as SAD?

[Katherine L.]

This is an interesting study regarding Vitamin D's role in seasonal affective disorder. I would like to see more research in this area. This study included only women. It would be nice to see a study that included men too. I wonder if they would get the same benefits. It would also be nice to see a study with a larger sample size.

[Amy]

After reading this study about vitamin D improving SAD symptoms, I looked up vitamin D on the Natural Standard Web site. There are many articles posted there about vitamin D. Apparently vitamin D deficiency is implicated in many various disease states, including bacterial vaginosis, colds, cystic fibrosis and inflammatory bowel disease, just to name a few. It certainly can't hurt to make sure we all get enough of this important vitamin.

[John]

Apparently, summer sunlight increases serotonin levels twice as much as winter sunlight. In layman’s terms, serotonin is essentially the “happy” neurotransmitter in the brain. It is the chemical naturally in the brain that many antidepressant medications act to facilitate. With winter sunlight increasing serotonin levels only half as much as summer sunlight, in addition to less daylight and less time outside during daylight hours, it is no surprise that seasonal affective disorder affects so many people in northern areas.

[John]

I did a quick PubMed search after reading this article regarding vitamin D and SAD symptoms. I found this interesting article: http://www.ncbi.nlm.nih.gov/sites/entrez. These researchers found that there was no association between vitamin D concentrations and depression. I would be interested in seeing more research in this area. I personally think it seems promising.

[Jess]

I was reading up on vitamin D. Apparently it is somewhat active in the brain. From what I understand, it is involved in some reactions that produce chemicals in the brain that transmit signals in the nervous system. It doesn’t really seem though like the entire process of how Vitamin D may improve symptoms of SAD is very well understood yet.

[Dentist McKinney]

This is a very informative post. So, does that mean that people who are often depressed have low levels of vitamin D?

[Amiya]

I also was unaware of an association between vitamin D and symptoms of seasonal affective disorder. I guess it does make sense since in the winter months, there isn't as much sunlight, so then you have less serum vitamin D. After reading this article, I thought I'd look into this relationship more, and I came across another study (PMID: 18793245) in support of serum vitamin D levels having an impact on symptoms of depression. Granted, this study was a little different (obese men and women from Norway) from the SAD one, but still interesting!

[Kara]

My endocrinologist warned me several years ago that most of the sun blocks we now use routinely block absorption of vitamin D. I would also be interested to know if depression occurs at other times of the year in someone who always uses sun block. Are we all just not getting enough vitamin D? There are very few nutritional sources with some fortification in cereals and milk.

[Lynn]

That is an interesting question, Kara. I also wonder if sunscreen affects our skin's ability to make vitamin D. Does anyone know how long a person needs to stay in the sun in order to get enough daily vitamin D? I have heard differing skin colors can affect the amount of time it takes to get adequate absorption.

[John]

So sun block doesn’t actually block the absorption of vitamin D, but rather blocks the ultraviolet rays, which help your body make vitamin D. Fortunately, it typically only takes 10-20 minutes of sunlight exposure to help make vitamin D, which is usually less than the time it takes to get burned, depending on the fairness of your skin. So, if you were going to be outside for a long period of time, it’s definitely a good idea to wear the sun block, but a short trip outside without the protection should be all right from a sun burn perspective and beneficial from a vitamin D production perspective as well.

[Jill]

It’s important to remember that just because this study has shown a potential benefit from vitamin D on SAD, it doesn’t mean that low vitamin D levels are the only reason that SAD occurs. It is also important to keep in mind that SAD is not just due to a lack of vitamin D because of a lack of sunlight. Sunlight, be it natural or from a light box, has been shown to improve mood and prolong fatigue. There is more at work here than just vitamin D due to lack of sunlight.

[Zoey F.]

This study investigated the effect of vitamin D on seasonal depressive disorder (SAD), but it did not mention anything about regular depression. I wonder whether SAD’s underlying mechanism is different from that of other types of depression or if SAD is simply a much milder case of depression. Whatever the case may be, this is a promising study, which warrants further research. Also, is there a reason why only women were included in the study?

[Dan]

I am very intrigued by this study. I have recently been looking at vitamin D. I mainly looked at the differences between vitamin D2, which is by prescription, and vitamin D3, which is available over-the-counter. My research revealed that the over-the-counter is more potent than the prescription. I want to know why the researchers picked vitamin D3 instead of vitamin D2. Does it have to do with the fact that it is more potent? I am also interested in if they will do a study on vitamin D and regular depression.

[Debra]

Although this study was not statistically significant due to its low patient population, taking vitamin D supplements could be an option for patients suffering from SAD. I found it interesting that all the participants were women because this patient population could potentially benefit from vitamin D supplementation. Taking vitamin D can help with dietary absorption of calcium, a mineral that helps with bone development that most women do not get enough of. I am just weary of people reading the study and then over supplementing with vitamin D -- is there a risk of toxicity over a certain blood concentration?

[Michelle D]

In the study discussed, only 9 women were assessed. This small study could not make any correlation for vitamin D supplementation with improving SAD symptoms. The correlation of SAD accompanied by vitamin D deficiency could be explained by the fact that SAD patients developed symptoms due to lack of sunlight exposure. We knew that adequate sunlight exposure is also critical for getting activated vitamin D. However, it would be important to note that lack of sunlight leads to SAD AND vitamin D deficiency. It did not imply that lack of sunlight leads to vitamin D deficiency, and therefore leads to SAD. Supplying SAD patients with activated vitamin D would not increase sunlight exposure. Therefore, SAD patients might not benefit from such supplement. More studies should be conducted to evaluate the relationship, if any, between vitamin D and SAD.

[Melissa]

It would be interesting to see another study in which they supplement with vitamin D in patients who don’t necessarily have low serum levels and to see if any improvements in seasonal affective disorder symptoms are seen. Also, it would be good to draw serum levels of vitamin D in patients who suffer from SAD to see the potential correlation between vitamin D levels and the disorder itself.

[M. Scott]

I’m sure that future studies will be conducted with larger and more diverse populations, including men and those with normal vitamin D3 levels. The investigators should also include serum levels of melatonin and serotonin at baseline to account for the effects of those neurochemicals on SAD. Since it is more likely that many chemicals are responsible for SAD symptoms, they should be able to more precisely define vitamin D3’s specific role in the disease. Vitamin D3 may turn out to benefit specific symptoms, as may serotonin and melatonin, and patient-specific therapies can be designed according to SAD symptoms.

[April Shaur]

As a sufferer of seasonal affective disorder, or appropriately termed SAD, I have tried many natural therapies, with mild-to-moderate success, to treat my symptoms. Since SAD is common in people who are deprived of vitamin D, it is common sense to link its treatment with vitamin D supplementation. Light boxes are also very effective, although expensive. However in my opinion, the best natural remedy for SAD is a plane ticket to a warm, tropical climate in the dead of winter, to get natural light and vitamin D! And trust me, it will probably cost you as much as a light box.

[d]

This is a very interesting study on the role of vitamin D. I do agree with the authors about the sample size being too small and that more people should be studied. Also, I noticed that they only surveyed women with low vitamin D levels. I can’t help but wonder if there are women with normal vitamin D level and SAD. Finally, to make sure that the mood improvement in this study wasn’t a placebo effect much more research is needed to support this finding.

[JB]

Vitamin D plays important roles in calcium absorption and bone metabolism. Some of the disease states like liver failure, malabsorption, rickets, decreased exposure to sunlight and osteomalacia, are commonly associated with low vitamin D levels. Also peopel who take medications, such as clonazepam, cerebyx, carbamazapine, depakote ER and other anticonvulsants, may also experience low vitamin D levels.

According to the Natural Standard grading scale, vitamin D receives a grade C for the treatment of seasonal affective disorder (SAD), meaning more studies are needed because of unclear or conflicting scientific evidence.

[James]

It may be possible that the women in the study underwent a placebo effect and felt less depressive symptoms knowing that they were receiving a treatment for their condition. Since there is no objective way to measure these depressive symptoms, it's hard to analyze the results of this study without a placebo group. However, it can be the basis for future well-designed studies on a larger scale. It would be interesting to see where this goes and if, in the future, people with SAD will be able to avoid antidepressants, which have a large side effect profile.

[Viburcol]

I have been using vitamin D since last year for my SAD, and I think it helped me, as things are much better now. I would recommend it :)

[pam]

For individuals with SAD, vitamin D supplementation would be a great alternative to other prescription medications, light boxes, etc. Light boxes are extremely expensive, and many individuals are uneasy about taking prescription medications.