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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Phototherapy improves quality of life, says new study

After atmospheric and ozone filtering, only about 3% of the total energy of sunlight at solar noon is ultraviolet, although that depends on latitude, season, altitude, and atmospheric conditions. The ultraviolet portion of outdoor sunlight is approximately 95% UVA and 5% UVB, although atmospheric, seasonal, and geographic variables change that ratio each time you step outside.

Doctor Laurence Feldmeyer, working under senior author Professor Gunther Hofbauer together with 13 co-authors, all of the University Hospital in Zurich, recently took a look at different UV wavelengths and what effect they had on vitamin D levels.

Feldmeyer L, Shojaati G, Spanaus KS, Navarini A, Theler B, Donghi D, Urosevic-Maiwald M, Glatz M, Imhof L, Barysch MJ, Dummer R, Roos M, French LE, Surber C, Hofbauer GF. Phototherapy with UVB narrowband, UVA/UVBnb, and UVA1 differentially impacts serum 25-hydroxyvitamin-D3. J Am Acad Dermatol. 2013 Jul 11.

Remember that ultraviolet light comes in three different categories, the shortest wavelength UVC (100 to 280 nm), which is very high energy and does not penetrate the atmosphere.

The final two ultraviolet wavelengths are UVB (280 and 320 nm), which both makes vitamin D and damages the DNA in our skin, and finally UVA (320 to 400 nm), which some studies indicate causes melanoma, but also may do something good in the skin that has yet to be discovered. For instance, dermatologists are using UVA phototherapy to successfully treat various forms of scleroderma (an autoimmune skin disorder) as well as rarer skin conditions. Therefore, UVA light clearly does something in the skin but we don’t know what it is

More on UVC

As an aside, a study from 70 years ago indicated that UVC is highly effective in both producing vitamin D and in treating rachitic rats.

Bunker JWM, Harris RS, Mosher LM: Relative efficiency of active wave-lengths of ultraviolet in activation of 7-dehydrocholesterol. J Am Chem Soc 1940, 62(3):508-511.

In 1982, Professor Michael Holick’s lab confirmed that UVC makes vitamin D. Per photon, UVC was more effective than UVB in making vitamin D in skin oils.

MacLaughlin JA, Anderson RR, Holick MF: Spectral character of sunlight modulates photosynthesis of previtamin D3 and its photoisomers in human skin. Science 1982, 216(4549):1001-1003.

Feldmeyer et al (in an open trial without randomization) used three different wavelengths of ultraviolet light [UVA alone, narrowband UVB alone (311 nm), and a combination of UVA and UVB] in 116 dermatological outpatients with various skin disorders, giving each group phototherapy two to three times per week for up to 12 weeks. Numbers in the various groups were UVA (n = 38), UVA/UVB (n =30), or UVB (n = 48).

They found that the UVA light group had a reduction in 25(OH)D levels (22 to 19.0 ng/mL (P=.001). However, narrowband UVB significantly increased 25 (OH)D levels from 22 to 40 ng/mL, as did combined UVA and narrowband UVB (24 to 50 ng/mL) phototherapy.

I found it interesting that combination UVA/UVB produced more vitamin D [peak 25(OH)D of 50 ng/ml] than did UVB alone (peak 40 ng/ml), although that difference was not significant. Before therapy with UVB alone there were 8 insufficient (

Blood pressure did not change in any of the 3 groups after treatment but all had normal blood pressures to begin with. They also observed no relationship between body weight and vitamin D serum change, confirming the results of previous studies.

Another interesting finding was that Dermatology Life Quality Index (DLQI) scores (a questionnaire aimed at detecting quality of life) improved in all the patients collectively (P<.001 and in each of the phototherapy groups considered separately. however there was no difference improvement dlqi scores between groups. score did not correlate with change although number completed questionnaires may have limited observed lack correlation to serum vitamin d changes.>

So UV light, including UVA, was what apparently improved quality of life, not improvements in 25(OH)D.

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

3 Responses to Phototherapy improves quality of life, says new study

  1. Rita and Misty says:

    Dear readers,

    I’ve posted this before, but the info is interesting (at least to me :) ), that I thought to share it again:

    Benefits of Sunlinght: A Bright Spot for Human Health

    I’ve also posted the below information previously:

    Sun-dependent pathways:

    1. Melatonin
    2. Serontonin
    3. Direct immune suppression

    Melatonin and Alzheimer’s disease:

    “Melatonin secretion decreases in Alzheimer´s disease (AD) and this decrease has been postulated as responsible for the circadian disorganization, decrease in sleep efficiency and impaired cognitive function seen in those patients. Half of severely ill AD patients develop chronobiological day-night rhythm disturbances like an agitated behavior during the evening hours (so-called “sundowning”). Melatonin replacement has been shown effective to treat sundowning and other sleep wake disorders in AD patients. The antioxidant, mitochondrial and antiamyloidogenic effects of melatonin indicate its potentiality to interfere with the onset of the disease. This is of particularly importance in mild cognitive impairment (MCI), an etiologically heterogeneous syndrome that precedes dementia. The aim of this manuscript was to assess published evidence of the efficacy of melatonin to treat AD and MCI patients. PubMed was searched using Entrez for articles including clinical trials and published up to 15 January 2010. Search terms were “Alzheimer” and “melatonin”. Full publications were obtained and references were checked for additional material where appropriate. Only clinical studies with empirical treatment data were reviewed. The analysis of published evidence made it possible to postulate melatonin as a useful ad-on therapeutic tool in MCI. In the case of AD, larger randomized controlled trials are necessary to yield evidence of effectiveness (i.e. clinical and subjective relevance) before melatonin´s use can be advocated.”

    Serotonin and Alzheimer’s disease:

    “Mounting evidence accumulated over the past few years indicates that the neurotransmitter serotonin plays a significant role in cognition. As a drug target, serotonin receptors have received notable attention due in particular to the role of several serotonin-receptor subclasses in cognition and memory. The intimate anatomical and neurochemical association of the serotonergic system with brain areas that regulate memory and learning has directed current drug discovery programmes to focus on this system as a major therapeutic drug target. Thus far, none of these programmes has yielded unambiguous data that suggest that any of the new drug entities possesses disease-modifying properties, and significantly more research in this promising area of investigation is required. Compounds are currently being investigated for activity against serotonin 5-HT(1), 5-HT(4) and 5-HT(6) receptors. This review concludes that most work done in the development of selective serotonin receptor ligands is in the pre-clinical or early clinical phase. Also, while many of these compounds will likely find application as adjuvant therapy in the symptomatic treatment of Alzheimer’s disease, there are currently only a few drug entities with activity against serotonin receptors that may offer the potential to alter the progression of the disease.”

    Pro-inflammatory cytokines and neuronal death:

    “Increasing concurrent evidence suggests that inflammation significantly contributes to the pathogenesis of AD. The generation and secretion of proinflammatory mediators may interact at multiple levels with neurodegeneration. Thus, proinflammatory cytokines may not only contribute to neuronal death, but they might also influence classical neurodegenerative pathways such as APP processing and τ phosphorylation.The concomitant release of anti-inflammatory mediators may partly antagonize this action ultimately leading to chronic disease. Future studies need to determine whether the course of AD can be influenced by anti-inflammatory treatment strategies, and clinically novel approaches to analyze early neuroinflammation in the human brain are needed to improve how to monitor and control treatment strategies that are targeting inflammatory mechanisms.”

    Vitamin D as anti-inflammatory agent

    “This newly identified DNA-binding site for the vitamin-D receptor, and the specific pathways inhibited by higher levels of vitamin D provide a plausible mechanism for many of the benefits that have been associated with vitamin D,” said Dr. Goleva. ‘The fact that we showed a dose-dependent and varying response to levels commonly found in humans also adds weight to the argument for vitamin D’s role in immune and inflammatory conditions.”

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  2. JBG says:

    The Feldmeyer et al DLQI results suggest placebo effects to me. Too bad they didn’t have a placebo group since, if the effects are real, it would be nice to be able to have confidence in them.

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  3. Rita and Misty says:

    I have not seen the DLQI instrument…yet I do think questionnaires in general provide shaky data at best…the questionnaire is a very subjective instrument in my opinion….

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