Seasonal affective disorder (SAD) is a type of winter-time depression experienced by people those who live in northern latitudes such as those of New York, Seattle, all of Canada, and Northern Europe. I believe it is primarily a disorder of sunlight/vitamin D deficiency.
Vitamin D, when administered in late winter, produces a positive effect on mood in only five days.[1] One theory for this is that vitamin D stimulates the brain to produce more serotonin. In a wintertime experiment, serum vitamin D levels doubled in six months through supplementation and dramatically increased scores on a wellbeing assessment.[2] Two groups were given either 1,000 IU or 4,000 IU of vitamin D daily. And although both groups improved, the higher dose produced better results.
Can vitamin D supplementation prevent winter-time blues? A randomised trial among older women.
Dumville JC, Miles JN, Porthouse J, Cockayne S, Saxon L, King C.
J Nutr Health Aging. 2006 Mar-Apr;10(2):151-3.
PMID: 16554952
CONCLUSIONS: Supplementing elderly women with 800 IU of vitamin D daily did not lead to an improvement in mental health scores.
Vitamin D vs broad spectrum phototherapy in the treatment of seasonal affective disorder.
Gloth FM 3rd, Alam W, Hollis B.
J Nutr Health Aging. 1999;3(1):5-7.
PMID: 10888476
All subjects receiving vitamin D improved in all outcome measures. The phototherapy group showed no significant change in depression scale measures. Vitamin D status improved in both groups (74% vitamin D group, p < 0.005 and 36% phototherapy group, p < 0.01). Improvement in 25-OH D was significantly associated with improvement in depression scale scores (r2=0.26; p=0.05). Vitamin D may be an important treatment for SAD. Further studies will be necessary to confirm these findings..
Association between depressive symptoms and 25-hydroxyvitamin D in middle-aged and elderly Chinese.
Pan A, Lu L, Franco OH, Yu Z, Li H, Lin X.
J Affect Disord. 2009 Feb 25. [Epub ahead of print]
PMID: 19249103
doi:10.1016/j.jad.2009.02.002
ScienceDaily (Mar. 18, 2009) - A lack of Vitamin D, due to reduced sunlight, has been linked to depression and the symptoms of Seasonal Affective Disorder (SAD), but research by the University of Warwick shows there is no clear link between the levels of vitamin D in the blood and depression.
Vitamin D and mood disorders among women: an integrative review.
Murphy PK, Wagner CL.
J Midwifery Womens Health. 2008 Sep-Oct;53(5):440-6. Review.
PMID: 18761297
Four of six studies reviewed imparted significant results, with all four showing an association between low 25(OH)D levels and higher incidences of four mood disorders: premenstrual syndrome, seasonal affective disorder, non-specified mood disorder, and major depressive disorder. This review indicates a possible biochemical mechanism occurring between vitamin D and mood disorders affecting women, warranting further studies of these variables using rigorous methodologies.
We compare the experts' advice and save you the time.
Current Evidence for the Benefits of Melatonin,
Dosage, Cautions and Interactions, Buyers Guide,
Sleep Tips, Jet Lag Remedies, Seasonal Affective Disorder,
Current News and Books.