Vitamin D

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I dunno if this will work. If it does it should be Aequalsz's paper:

Abstract

As early as 1930 sunlamps claiming to provide ultraviolet (UV)

exposure to make vitamin D were sold to the public in the US and

Canada for home use. Today even with dietary supplementation of

vitamin D many people do not get enough solar UV exposure to maintain

sufficient vitamin D levels. There is growing interest in the

availability of sunlamps for this purpose. The original Sperti

Sunlamp, with label claiming vitamin D benefit was approved by the

American Medical Association in 1940 as a sunlamp. This intermediate

pressure mercury lamps ultraviolet B emission lines, at 297, 302, and

313 nm are able to convert 7-dehydrocholesterol in the skin to

vitamin pre-D3 initiating the natural process of vitamin D formation.

Today's KBD Vitamin D lamp, an updated model of the earlier type

source. In order to comply with modern safety guidance, the source is

filtered to remove unnecessary UVC radiation and is equipped with a

timer to control the dose administered. The 5 min timer provides an

exposure, at 20 in. from the user's skin, of one standard erythemal

dose (SED). The SED represents a suberythemal dose for even the most

sensitive skin type I individual.

Keywords: UV; UVC; UVB; UVA; Vitamin D action spectrum; Erythema

action spectrum; Sunlight; Solar altitude; Mercury lines

Article Outline

1. Introduction

2. Methods

3. Results

4. Discussion

Disclosure of interest

References

1. Introduction

The UV spectrum of sunlight varies continuously throughout the day

and year, so that a given exposure 1 day, effective for vitamin D

without risk of sunburn, can on another day result in sunburn without

significant vitamin D benefit. The difficulty of making natural

vitamin D in skin in the winter or at higher latitudes, over 40°, is

well documented [1], [2] and [3].

In the US during the 1930s, 1940s and into the 1950s mercury sunlamps

were sold with claims that the UV produced beneficial vitamin D. Such

UV lamps were evaluated by the American Medical Association and

approved for use as sun tanning lamps, phototherapy lamps and lamps

useful for the production of vitamin D [4].

After the formation of the FDA Center for Devices and Radiological

Health (CDRH), the FDA assumed formal regulation of these UV devices.

The FDA established policy that such UV devices could have labeling

only for a single use, i.e. sunlamps for tanning may only be labeled

relative to tanning and the risks of tanning. Consequently, today

there are no commercially available UV lamps making claims and

providing directions for safe (no risk of sunburn) exposure to

produce vitamin D. In this study, the newly available Sperti Vitamin

D UV lamp and a circa 1950 Sperti P-104 UV lamp marked with vitamin D

claims (Fig. 1) are spectrally compared and evaluated relative to

sunlight for vitamin D effectiveness.

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Fig. 1. Vintage Sperti P-104 1950s UV lamp and New KBD DUV lamp. The

classic Sperti P-104 lamp (upper panel) made package and instruction

booklet claims of inducing vitamin D in irradiated skin. Note a

simple toggle switch on the right side turns the lamp on and off.

When this lamp was manufactured timers were not required to control

exposure. The modern KBD Vitamin D lamp (lower panel) is manufactured

according to today's GMP standards. There is a timer to control

exposure administered.

2. Methods

The spectra of the new KBD (Sperti) Vitamin D lamp along with a

historic 1950s vintage Sperti P-104 lamp (Fig. 1) was measured at 1

nm intervals with an Optronic Laboratories model OL 754

spectroradiometer. The OL-754 was configured with 0.25 mm/1.00

mm/0.25 mm slits and a 4-in. integrating sphere with a 32 mm entrance

aperture to collect the radiation and was calibrated using an

Optronic Laboratories spectral irradiance standard traceable to NIST.

The lamp spectra along with a set of solar spectra reported earlier

[5] were analyzed using two spectral weighting curves, the CIE

standard erythema dose analysis [6] and a redigitized version of the

originally published vitamin D action spectrum [7]. Relative benefit

to risk was evaluated by calculating the ratio of vitamin D effective

irradiance to erythemal effective irradiance of the UV lamp compared

to solar spectral variations.

3. Results

Spectral comparison of the new Sperti Vitamin D lamp with the circa

1950s Sperti lamp shows the most striking difference is that the

earlier lamp emits UVC (200–280 nm) lines that the glass envelope

currently used blocks (Fig. 2). All other mercury lines emitted by

the historic unit are still present. The FDA guidance document for

indoor tanning lamps requires that UVC radiation be blocked or

removed from indoor tanning sources [8].

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Fig. 2. Spectra of historic and new vitamin D lamps. The historic

Sperti P-104 lamp spectrum (dotted line) is compared to the new KBD

DUV lamp (solid line). The significant difference between the two

spectra is the presence of very short wavelength UVC radiation in the

historic source.

Like the historic Sperti 104 Sunlamp, the newly developed KBD Vitamin

D lamp emits wavelengths effective in production of vitamin D in skin

(Fig. 3). Assessment of possible benefit of exposure to risk shows

the spectrum of the KBD Vitamin D lamp is comparable to moderate late

morning or early afternoon solar spectra (Fig. 4).

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Fig. 3. Overlap of vitamin D action spectrum and KBD Vitamin D lamp.

On a normalized linear plot the vitamin D action spectrum from

MacLaughlin et al. [7] (dotted line) overlaps the UV emission lines

of the KBD Vitamin D lamp spectrum (solid line). Mercury lines at

297, 302, and 313 nm are seen to over lap as well as several much

smaller shorter wavelength lines. UV mercury lines at 335 and 366 nm

cannot produce vitamin D.

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Fig. 4. Vitamin D effectiveness/erythemic risk vs. solar altitude.

Efficient production of vitamin D in skin by sunlight is dependent

upon the specific solar altitude (symbols associate time and solar

altitude in degrees versus effectiveness ratio). Note that low solar

altitudes before 8 a.m. or after 4 p.m. cannot produce vitamin D as

well as high altitude sunlight. The Dashed line positions the

effectiveness to risk ratio of the KBD Vitamin D lamp relative to

sunlight.

4. Discussion

Today our understanding of acute UV risks, like sunburn [6] or

pigmentation [8] and long term risks of UV exposure, based upon

animal data, like photoelastosis [9] and photocarcinogenesis [10]

allows for both acute and chronic risks to be reduced by minimizing

excess exposure while obtaining appropriate exposure to promote

vitamin D synthesis.

The primary advantage of the new KBD Vitamin D lamp over its

predecessor is the addition of an exposure timer. At 20 in. the 5 min

maximum timer of the new lamp delivers one standard erythemal dose

(SED) or 10 mJ/cm2 erythemally effective exposure per use. Repeated

exposure to the same area over time will cause tanning, so it is

recommended to change the part of their body exposed with each

session. Minimization of tanning similarly reduces chronic UV

exposure risks to while allowing maintenance of suitable vitamin D

levels.

The benefit to risk of the KBD lamp (Fig. 4) indicates that users can

expect the vitamin D benefit relative to acute exposure risk

comparable to moderate intermediate altitude sunlight. Reliance on

sunlight (Fig. 4) does not assure that equally timed exposures will

produce the same amount of vitamin D or the same risk of acute or

chronic injury. Our analysis suggests that advice on daily or

periodic sunlight exposure for vitamin D maintenance should be more

complex than current advice. Individuals choosing to use sunlight may

be wise to acclimatize those parts of their bodies to be exposure

through daily exposures to minimize the possibility of sunburn.

Disclosure of interest

RMS and JCD are paid consultants of Sperti Sunlamps on the vitamin D

lamp project. The Department of Dermatology at UT has received

equipment and other support from the UV Foundation and Sperti

Sunlamps.

References

[1] M.G. Kimlin, A.V. Parisi and N.D. Downs, Human UVA exposures

estimated from ambient UVA measurements, Photochem. Photobiol. Sci. 2

(2003) (4), pp. 365–369. Abstract + References in Scopus | Cited By

in Scopus

[2] M.G. Kimlin and K.A. Schallhorn, Estimations of the

human `vitamin D' UV exposure in the USA, Photochem. Photobiol. Sci.

3 (2004) (11–12), pp. 1067–1070. Abstract + References in Scopus |

Cited By in Scopus

[3] A.R. Webb, L. Kline and M.F. Holick, Influence of season and

latitude on the cutaneous synthesis of vitamin D3: exposure to winter

sunlight in Boston and Edmonton will not promote vitamin D3 synthesis

in human skin, J. Clin. Endocrinol. Metab. 67 (1988) (2), pp. 373–

378. Abstract + References in Scopus | Cited By in Scopus

[4] The Council on Physical Therapy, Sperti irradiation lamp model H-

41 acceptable, J. Am. Med. Assoc. 117 (1941) (1), pp. 33–34.

[5] R.M. Sayre, J.C. Dowdy, J. Shepherd, I. Sadiq, A. Baqer, N.

Kollias, Vitamin D -vs- erythema: effects of solar angle & artificial

sources, in: M.F. Holick, E.G. Jung (Eds.), Biologic Effects of Light

1998, Proceedings of a Symposium, Basel, November 1–3, 1998, Kluwer

Academic Publishers, Boston, 1999, pp. 149–152.

[6] CIE Technical Committee 6-40: CIE Standard 007/E:1998, Erythema

Reference Action Spectrum and Standard Erythema Dose, Commision

Internationale de l'Eclairage (CIE) Central Bureau, Vienna, Austria,

1998.

[7] J.A. MacLaughlin, R.R. and M.F. Holick, Spectral

character of sunlight modulates photosynthesis of previtamin D3 and

its photoisomers in human skin, Science 216 (1982) (4549), pp. 1001–

1003. Abstract + References in Scopus | Cited By in Scopus

[8] W.E. Gundaker, Policy on maximum timer interval and exposure

schedule for sunlamp products. Center for Devices and Radiological

Health, Food and Drug Administration, 1986,

www.fda.gov/cdrh/radhlth/pdf/sunpol01.pdf.

[9] L.H. Kligman and R.M. Sayre, An action spectrum for ultraviolet

induced elastosis in hairless mice: quantification of elastosis by

image analysis, Photochem. Photobiol. 53 (1991) (2), pp. 237–242.

Abstract + References in Scopus | Cited By in Scopus

[10] F.R. de Gruijl, H.J. Sterenborg, P.D. Forbes, R.E. Davies, C.

Cole, G. Kelfkens, H. van Weelden, H. Slaper and J.C. van der Leun,

Wavelength dependence of skin cancer induction by ultraviolet

irradiation of albino hairless mice, Cancer Res. 53 (1993) (1), pp.

53–60. Abstract + References in Scopus | Cited By in Scopus

Corresponding author at: RMS, Rapid Precision Testing Laboratories,

P.O. Box 1342, Cordova, TN 38088-1342, United States. Tel.: +1 901

386 0175; fax: +1 901 386 7218.

http://snipurl.com/1hyi8

Rodney.