MVB info

[NicoleRussell]

This is a letter which has been copy and pasted from the meter group, just some FYI:Pay particular attention to Bob's response:


Brian wrote >>First I want to let you know Bob that I'm not trying to
dispute you with what I'm about to say,you know alot more about this
than I do. What I said is based on some info that I was given by
zoomed ( that was the stuff about what the 5% and 8% on a bulb
means ).<<

Robert wrote >>I'm confused here. Regardless of anything else, if
the 6.2 meter registers
good numbers, is it not simply the case that higher numbers over time
indicate a better bulb for UVB production?<<

Hello Brian and Robert,

(all new friends, please read the "files section")

I will address both comments on this post. This is important
information for the group so I recommend that all read it.

Below is some information that I copied from MK's site. This is not
MK's writing but that of Dr Gehrmann.(Melissa has some of the VERY
best information on the web on her site, but because of her fear of
UV, it also houses some of the worst information on the web.) I have
read Melissa's site in its entirety several times.

The information about percentages and florescent tubes can be found
on many sites on the web and has been confirmed by the florescent
manufacturers themselves to me personally. This is important because
otherwise people would believe the bigger the % given on the box, the
better the UVB. This just isn't the case. Many 7.0 and 8.0 bulbs just
don't produce much UVB, and the ones that do may not produce much D-
UV.

This is why ZooMed is so concerned about our broad-band meters. Their
5.0 florescent bulb MAY NOT PRODUCE AS MUCH TOTAL UVB as some other
bulbs, although it *may well* in reality produces more D-UV then the
higher reading lamps.

As a simple example, you buy fruit punch because you want to drink
healthy. One brand has 10% fruit juice and is 10oz's but cost $2,
another brand contains 2% real fruit juice, is 16oz's and only cost
$1. Which is really the better drink? That would depend on whether
you are looking for quality, or volume and cost.

Gehrmann's article below is incomplete. I will post this in its
entirety in "Files section"

"Are All Wavelengths of UVB Equally Effective in Promoting Vitamin D3
Synthesis?

UVB is generally defined as the wavelength band from 290-320nm. Based
on data by MacLaughlin, Anderson, and Holick (1982), 1 have
calculated that about 60% of D3 is produced between 290-300nm.
Because most D3 is synthesized within this narrow subdivision of UVB
(between 290-300nm), the range has been termed D-UV (Bernard, 1995).
The lamps in Table 1 use a phosphor that peaks at about 313nm.
Therefore most of the UVB emitted is at wavelengths greater than 310
nm. Only about 5 % of D3 results from wavelengths greater than 310 nm.

Does This Mean the Lamps are Ineffective in Promoting Vitamin D 3
Synthesis?

Not necessarily. The effectiveness of a lamp will depend on the
species, the length of exposure time, the distance to the lamp as
well as dietary and thermal factors. Also, most of the lamps in Table
1 do emit some energy at the ideal D3-producing wavelengths. The only
experimental studies I know of pertaining to the effectiveness of
lamps for longterm health and reproduction involve chameleons,
Chamaeleo, and are being conducted principally in Gary Ferguson's lab
at Texas Christian University, with several zoos participating in
some of the work.

Is There a Reptile Lamp That is Safe and Specifically Designed to
Maximize Vitamin D3 Synthesis?

An experimental lamp using a special phosphor that peaks at about
296nm has been tested and been shown to be effeclive in promoting D3
synthesis and elevating blood D3 metabolites in iguanas (Bernard,
1995). Manufacturing and marketing activities are currently underway
and this "Sylvania 2096 Experimental Reptile light" may be available
sometime in 1997 (Bernard, personal communication).
What do the Numbers Sometimes Used to Describe Reptile Lamps Mean?
Numbers, such as 2% or 8%, or in decimal form, such as 5.0 or 2.0,
refer to the percentage of total energy emitted from the lamp between
290nm and 700nm (UV and visible light) that is UVB (290320nm). These
numbers can be used to compare relative UVB emission among lamps, but
can not be directly related to the irradiance or the distribution of
energy at different wavelengths within the UVB band or the D3
synthesizing capability.

Will Reptiles Regulate Their Exposure to Ultraviolet Light?

Jones et al., (1996) reported that female panther chameleons, C.
pardalis, receiving low levels of dietary D3 or preparing to oviposit
will behavioraly increase their exposure to UV light, compared to
controls, in a UV gradient. This exciting observation requires
further exploration with respect to other species and mechanisms. The
study suggests that it might be judicious to include shaded areas in
vivaria receiving relatively high levels of UVB.

Is There a Component of Natural Light That May Be More Important Than
Light Quality?

In a recent issue of The Vivarium, Gehrmann (1996) mentioned a
considerable body of literature that emphasizes the importance of
infrared radiation (heat) for thermoregulation. Some species,
particularly nocturnal forms, may preferentially utilize heat
radiated from the substrate rather than from sunlight. Diurnal
basking species however receive both light and infrared radiation
when they bask. Sievert (1991) has shown that spatial separation of a
light and a heat source can lead to alteration of thermoregulatory
behavior. While the importance of this for longterm health has not
been demonstrated, I suggest that it may be desirable to use a
reflector lamp as a combined heat and light source, particularly for
basking species, with adjunct light sources placed where convenient."

best,

Bobmac

	Ultra Violet Radiation B Ultra Violet Radiation B

[suzi]

Color me stupid, but HUH???

[mello]

exactly

[NicoleRussell]

I'm trying to take info that has the most importance and bring it over
There was a delay in meter delivery but mine should be here this week sometime. At that point I should be able to post personal findings and I'll try to put it into a more readable language. I have gotten used to Bob's posts after reading them for a while, I forgot many of you have never even heard of him
In any case, if you can sift through the info it's great material.
So far the bulbs that are best for animals who reuire UVB are:
Westron (though the heat factor is not enough so it must be coupled with another heat source) and Trex spots.
These have proven the best for overall quality, animal health, and consumer problems.
I was using tubes, and made the switch to MVBs a while ago---now I'm switching to the bulbs who seemed to test the best.
These animals were even given blood tests...they leave no stone unturned.
I will get back to everyone as more info is made clear to me and as I get results from my own findings.

	Ultra Violet Radiation B Ultra Violet Radiation B