GB2531907A

GB2531907A - A device and method for stimulating vitamin D3 synthesis in equine skin

Info

Publication number: GB2531907A
Application number: GB1516404.9A
Authority: GB
Inventors: Auckland John; Auckland Lisa
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-09-16
Filing date: 2015-09-16
Publication date: 2016-05-04
Anticipated expiration: 2035-09-16
Also published as: GB2531907B; GB201416378D0; GB201516404D0

Abstract

A device which stimulates vitamin D3 synthesis in equid skin. The device comprises: one or more ultraviolet (UV) lamp 1, 2, 3, 4; one or more heater 5, 6; and a controller having one or more switch to turn the one or more UV lamp and the one or more heater on and off at predetermined times. UV lamp may be a high vitamin D 3 yield index lamp. UV lamp may produce at least 6%, 18%, 20%, 25%, 30%, 35%, 40%, 45%,50%, 55%, 60%, 70%,80%, 90% of its total UVB output in the range 295-314 nm. UV lamp may produce no more than 82%,80%,75%,70%,65%,60%,55%,50%,40%,30%, 20%,10% of its total UVB output in the 315-330 nm range. UV lamp intensity may be varied. Heater intensity may be varied. Heater may be an infrared (IR) heater and may have a peak output of 1200nm. Several preferable on times are specified before the predetermined off time. Also a method of stimulating vitamin D3 synthesis in equid skin using the device.

Description

A device and method for stimulating, Vitamin D3 synthesis in equine skin The invention relates to devices and methods for meeting the Vitamin D requirements of stabled horses and other equids.

Vitamin D is vital to the normal development and maintenance of health of horses just as it is to all living invertebrates. Vitamin D is required as it helps the animal absorb important calcium and phosphorous in its food This increases bone mineralization in growing horses and maintains bone health in older horses. It also helps with insulin secretion and regulates normal cellular differentiation thus preventing cancer.

In most species of invertebrates a deficiency of Vitamin D results in rickets in the young and inadequate bones mineralization in the adult. In severe or chronic cases affected horses can become soft and flexible resulting in bowed legs. Even a mild Vitamin D deficiency will result in a dull, matted coat. The most striking feature of Vitamin D deficiency, however, is emaciation.

Vitamin D3 is created naturally in the skin through exposure to the sun's Ultraviolet (UV) radiation. UV light occurs naturally in sunlight. For practical purposes the UV range is divided into different bands including UVA (315-400nm), UVB (280-315nm) and UVC (100-280nm).

A horse's hair oat, combined with melatoni n in the horse's skin creates such a significant barrier to UV radiation that it typically takes 5 to 8 hours of exposure to sunlight daily for horses to synthesize their full Vitamin D requirement.

Vitamin D3 is synthesized in equine skin in response to UVB light using the following steps: i) 7-dehydrocholesterol (7DHC) or provitamin D3 is synthesized in the intradermal skin layer in response to UVB wavelengths between 270nm and 320nm.

ii) Provitamin D3 is held within the cell membrane and is then converted rapidly to previtamin D3.

iii) Previtamin D3 is then isomerised slowly in warm skin over several hours to make Vitamin 133.

Peak synthesis of provitamin D3 occurs at 298nm and tapers off as the UV wavelength increases. At a wavelength of 314nm synthesis is less than 5% as efficient as at 298nm. UVB levels increase significantly as wavelength increases, such that in sunlight, there is typically over 50 times more UVB at 314nm than there is at 298nm.

Natural sunlight is filtered by the Earth's atmosphere, and all wavelengths of UVB shorter than 290nm are filtered out, irrespective of the sun's inclination. Unless the sun is directly overhead, atmospheric filtering of sunlight typically produces a threshold for available natural UVB of 295nm to 300nm. Atmospheric filtering is important because wavelengths shorter than approximately 295nm cause DNA damage and kill living cells.

Skin temperature plays a very important role in the synthesis of Vitamin Di Warmth is needed for the reaction to proceed at a normal rate. Outside, warmth is provided through infrared (1R) radiation from the sun.

Vitamin D3 is transferred to the liver by the Vitamin D binding protein where it is converted to calcidiol (25-hydroxycholecalciferol, 25[OH] D3).

Calcidiol is then transferred to the kidneys which in association with the hormone parathyroid further converts it to calcitriol (1, 25 dihydroxycholecalciferol, 1,25[0M2D3) Studies suggest that both calcidiol and calcitriol have their own significant role in the operation of the organic system: calcidiol acts as a hormone and controls for example cell division whereas calcitriol is the active substance which regulates the calcium level of blood serum. For convenience both calcidiol and calcitriol are commonly called Vitamin D. Until recently it was thought that only the kidneys could activate Vitamin D. It is now known that a variety of cells have this ability, including those in the breast, prostate, colon, brain and most importantly the skin. Activated Vitamin D which is manufactured in these cells is consumed locally hence it does not enter the bloodstream to create Vitamin D toxicity.

If excess Previtamin Di is formed in the skin, it is further photo-isomerised by UVB radiation to lumisterol and tachysterol, via a rapid photo-reversible reaction. Thus a natural regulation system operates to prevent excess Vitamin D3 from accumulating under strong UVB conditions. The four substances, 7DHC, previtamin D3, lumisterol and tachysterol are held in equilibrium within the skin, such that when Vitamin D3 is carried away in the bloodstream, this promotes the formation of more previtamin D3.

Vitamin D2 (ergocalciferol) can also be obtained through the diet. Vitamin D2 is produced in the dead leaves of plants when exposed to sunlight and in the dead leaves of living insolated plants. Thus sun dried hay which has not been stored for more than one season and dormant sun-cured pasture forage can be useful sources of Vitamin D2.

Although Vitamin D2 and Vitamin D3 perform the same functions once inside a horse's body. Vitamin Deis much less potent than Vitamin D3 and its availability reduces as these food sources are stored. During dry-feed storage, Vitamin D2 potency decreases at an average rate of 7.5% per month. Potency after 1 year is reduced to 39% of the original amount and to just 15% after two years storage.

It is generally accepted in the field of equine care that if a horse is fed on sun-cured hay or forage or is allowed to be in the un-shaded open air for several daylight hours a day its Vitamin D requirements should be met. However modern equine management practices such as stabling and rugging dramatically limit horses' exposure to natural sunlight. This is particularly the case with valuable equine athletes and breeding horses which are stabled much of the time for ease of management, physical security and to reduce the risk of injury.

UVB cannot penetrate the walls and roofs of stable buildings nor does it pass successfully through glass. Normal window glass excludes 22% of UVA and 96% of UVB radiation.

When outside, rugs are routinely worn to protect the horse from cold, wind and rain. A standard three-seasons horse rug covers at least 80% of the equine's body. In temperate climates horses are routinely rugged for eight or nine months of the year. Horse rugs block nearly all UV light.

During warmer weather horses are often stabled during the middle part of the day when UV levels are highest to avoid the nuisance of flies and limit over-eating of rich grass. Again this limits exposure to natural UV light.

In summer horses often wear light fly sheets to protect the horses from biting insects which can causes lumps and irritation or skin conditions such as sweet itch. To be properly effective a fly sheet would normally cover up to 95% of the horse, preventing most of the horses body from receiving any UV light.

Hence even when they are turned out the equine is exposed to very little UV light. Hence the potential to synthesize Vitamin D3 is severely restricted.

Exposure to UV light during exercise periods may be further restricted. A racehorse, for example, may be exercised for only 30 to 40 minutes per day and will generally wear a light fleece covering during exercise which covers most of its upper body. Competition or riding horses are often exercised in an indoor school (manage).

Fly spray, coat conditioner, or decreased body oils due to bathing may further undermine a horse's capacity to synthesize Vitamin D3 in its skin.

It is common general knowledge in the art that if a horse is not fed sun-cured hay or pasture forage cured for less than one season and is not given any access to direct sunlight for periods in excess of several months its dry feed should be supplemented with crystalline Vitamin D in the following amounts: Rapid growth and early lactation 0.545 pg/kg Late pregnancy 0.571 pg/kg Maintenance of condition 0.5 µg/kg However Vitamin D supplementation carries a significant risk of over dosing.

Vitamin D toxicosis is the most common of all Vitamin toxicosis. It arises as a result of improperly formulated feeds, administration of excessive oral or injected Vitamin D, or ingestion of Vitamin D glycosides found in some parts of the World (including Florida, Texas and southern California).

Vitamin D toxicosis results in a range of clinical symptoms including: Decreased exercise performance and tolerance Increased concentration of phosphorous in the blood Weight loss or decreased growth rate Stiffness and sensitive tendons and ligaments Decreased diet Impaction of the bowel Increased resting heart rate Decreased renal function increased urination and drinking Gradual loss of condition and reduced activity.

Vitamin D concentration begins to increase on the first day of excess Vitamin D consumption. As the effects of excess Vitamin D are cumulative it may take many months for its effects to become evident and even longer to be diagnosed through plasma testing. Especially as the signs of toxicity are similar to Vitamin D deficiency, reduced feed intake, poor growth, and an unthrifty appearance.

Once a diagnosis is made it can take several months for the imbalance to be corrected.

Commercially available UV lamps which are intended to promote Vitamin D3 synthesis in vertebrates have widely differing spectral characteristics. Some do not replicate the natural UVB spectrum of the sun sufficiently well to be of significant benefit to equids.

Some commercial UVB lamps which emitted very small amounts of UVB in the region of 280-295nm are known to have injured a hundred reptiles and in 10% of cases the reptiles died.

Extreme caution is therefore required, even with UV lamps described as being of medical quality, as at best, they could be of no use, and potentially they could cause harm to equids.

Stabled horses are at high risk of developing Vitamin D deficiency the health consequences of which can be very serious especially for equine athletes. In cases of severe deficiency, Vitamin D may need to be administered by injection.

A need exists for safe, effective technologies which allow horses that live predominantly in stables to synthesize sufficient Vitamin D3 in their skin to meet their Vitamin D requirements and avoid the toxicity risks associated with Vitamin D supplementation.

In a first aspect the invention relates to a device which in use stimulates net Vitamin D3 synthesis in equine skin comprising: a) one or more UV lamp; b) one or more heater; c) a controller comprising one or more switch to turn the one or more UV lamp and the one or more heater on and off at predetermined times.

In a further aspect the invention relates to a device wherein the one or more UV lamp is a high Vitamin D3 Yield Index lamp.

In a further aspect the invention relates to a device wherein the one or more UV lamp produces at least 6%, 18%, 20%, 25%, 30%, 35%, 40%, 45%,50%, 55%, 60%, 70%, 80%, 90% of its total UVB output in the range 295-314nm.

In a further aspect the invention relates to a device wherein the one or more UV lamp produces no more than 82%,80%,75%,70%,65%,60%,55%,50%,40%, 30%, 20%, 10% of it's total UVB output in the 315-330nm range.

In a further aspect the invention relates to a device wherein the intensity of the one or more UV lamps can be varied.

in a further aspect the invention relates to a device wherein the intensity of the one or more heaters can be varied.

In a further aspect the invention relates to a device wherein the heater is an IR heater preferably a shortwave IR emitter.

In a further aspect the invention relates to a device wherein the heater has a peak output of 1200nm.

In a further aspect the invention relates to a device wherein the predetermined on time is 40 minutes, 50 minutes, 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,or 18 hours before the predetermined off time In another aspect the invention relates to a method of stimulating Vitamin D3 synthesis in equid skin using the device.

Description of the Drawings

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a horse being treated using a device of the present invention.

Figure 2 shows UVB measurements taken throughout a clear day in the UK in August to provide an indication of typical daytime UVB levels.

Figure 3 shows how the UVB lamp or lamps may be switched or modulated in a timed, stepped sequence to mimic the UVB output of the sun.

Detailed Description:

With reference to figure 1 the device of the present invention comprises one or more UV lamps 1,2,3,4 one or more heater 5,6 and a controller for switching the one or more UV lamps and the one or more heaters on and off at predetermined times.

Preferably the one or more UV lamps 1,2,3,4 and the one or more heater 5,6 are located on a supporting arm or frame 7.

The device can be used to treat one or more horse 12 The device is intended to be installed in the horse or horses living quarters to create a UV basking zone in which the horses body is exposed to UV light. Warmth generated by the device can extend outside the UV basking zone.

Preferably the one or more UV lamp and the one or more heater are switched on for one or more treatment period of 40 to 50 minutes duration.

More preferably the one or more treatment period is of 1,2,3,4,5,6,7,8,9,10,11,12, 13,14,15,16,17,18 hours duration.

Referring to figures 2 and 3 by way of example only the UV lamps may be switched on and off during the treatment period, to simulate the changes in UVB output of the sun on a clear day, as follows: i) one UV lamp 1 being switched on for 2 hours then; ii) two UV lamps 1 and 2 being switched on for 2 hours then; iii) three UV lamps 1,2 and 3 being switched on for 1 hour then; iv) four UV lamps 1,2,3 and 4 being switched on for 2 hour then; v) three UV lamps 2,3 and 4 being switched on for 1 hour then; vi) two UV lamps 3 and 4 being switched on for 2 hours then; vii) one UV lamp 4 being switched on for 1 hour Alternatively UV lamp output may be modulated, for example using dimmable 1-10V ballasts.

Preferably the one or more UV lamps are high quality UV emitting devices with no detectable emissions below 295nm, significant UVB emissions in the range from 298nm to 315nm, and high levels of UVB emissions in the range 315nm to 335nm.

More preferably the UV lamp produces 0% of its total output in the UV range below 295nm.

More preferably the UV lamp produces at least 6%, 12%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90% of it's total light output in the UVB range above 295nm.

The one or more heaters 5, 6 should provide sufficient warmth, depending on the ambient temperature, so that horse or horses being treated does not need to be rugged.

The one or more heaters 5, 6 should provide sufficient warmth to isomerise previtamin D3 to Vitamin D3 in the skin or the horse or horses being treated. Preferably the heaters 5, 6 will be shortwave infrared emitters with a peak output around 1200nm (the shortwave or IR-A region covers wavelengths of 800-1400nm).

Frequencies in the region of 1200nm are absorbed effectively into the horse's dermis, warming the skin tissue directly.

The controller comprises one or more switch to turn the one or more UV lamps and the one or more heater on and off automatically at pre-determined times.

Preferably the controller further comprises means for varying the UV intensity of the one or more UV lamps during the treatment period. This allows the UV intensity to be varied to mimic the changing intensity of the sun during a day, a season or a year.

Preferably the controller further comprised means for varying the total UV output of the one or more UV lamps during the treatment period. This allows the total UV output to be varied for different breeds of horse which may have different sunlight requirements e.g. Welsh cobs may require less UV light than Arab horses.

Preferably the controller further comprises means for varying the total UV output of the device to allow the device to be located at different distances from the horse.

Preferably the controller further comprises means for varying the heater output. This allows the heater output to be varied depending on the ambient temperature of the stable at different times of the day, season or year.

In use the device can be used to expose the horse to sufficiently high levels and durations of UV light to mimic natural sunlight conditions and enable the horse to produce Vitamin D3 naturally in the skin, using exactly the same biological mechanism that would be used if the horse were in the open outdoors, exposed to the UV and warming infrared radiation of the sun.

The device can also be used as a conventional solarium either by switching off the one or more UV lamps or by reducing the intensity of the one or more UV lamps output.

Claims

Claims: 1. A device which in use stimulates net Vitamin D3 synthesis in equid skin compri sing: d) one or more UV lamp; e) one or more heater; 0 a controller comprising one or more switch to turn the one or more UV lamp and the one or more heater on and off at predetermined times.
2. A device as claimed in claim 1 wherein the one or more UV lamp is a high Vitamin D3 Yield Index lamp.
3. A device as claimed in claim 1 or claim 2 wherein the one or more UV lamp produces at least 6%, 18%, 20%, 25%, 30%, 35%, 40%, 45%,50%, 55%, 60%, 70%, 80%, 90% of its total UVB output in the range 295-314nm.
4. A device as claimed in any one of claims 1 to 3 wherein the one or more UV lamp produces no more than 82%,80%,75%,70%,65%,60%,55%,50%,40%, 30%, 20%,10% of it's total UVB output in the 315-330nm range.
5. A device as claimed in any preceding claim wherein the intensity of the one or more UV lamp can be varied.
6. A device as claimed in any preceding claim wherein the intensity of the one or more heater can be varied.
7. A device as claimed in any preceding claim wherein the heater is an IR heater.
8. A device as claimed in claim 7 wherein the heater has a peak output of 1200nm.
9. A device as claimed in any preceding claim wherein the predetermined on time is 40 minutes, 50 minutes, 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,or 18 hours before the predetermined off time.
10. A method of stimulating Vitamin D3 synthesis in equid skin using the device claimed in any preceding claim.