In his book "HPU and then..?" Dr. Kamsteeg writes: "It is important to not use vitamin B6,
biotin, multivitamins, pyridoxal-5-phospahe or zinc in the
week prior to the urine collection. In case of long-term use
of 50mg or more of vitamin B6 per day, the test may turn out
to be ‘false-negative’. This means that the result of the test is
‘negative’, while under normal conditions you would have had
a positive result. Also after a period of relaxation, i.e. after a
vacation or sickbed it is better not to send the test, because the value will then be much lower." "When
you’ve urinated a lot in the night prior to the test, then
select another day. If you have to urinate in the night after 4
AM (with a normal night’s rest), consider this urine then as
morning urine. If you drink a lot of water, do not drink extra
water the day before the test. Also do not drink large amounts
of alcoholic drinks the day prior to the urine collection.
It is best not to send in urine the first days after the
menstruation, because the values are a lot lower then than
average."
"The test (HPU) is completely reliable, subject to the condition that it
is performed under the right circumstances. There are some
factors that can influence the test results. There is a group of so-called ‘evening-excreters’.
In most people, most of the HPL-complex is excreted
in the first morning urine (see fi gure 1a). In them the
HPL-complex accumulates in the urine during the night.
Normally we notice a decrease after in the curve after an
initial value of 1,2 μmol/l in the morning urine. It is even
possibly that by noon, nothing can be detected in the
urine anymore. After this the value increases again in the
afternoon to end in the evening at a relatively high value.
The following morning we’ll then detect the highest value of
the day again.
This image is different in chronically ill people (see figure 1b). These people are not able to temporarily accumulate
HPL- or it’s precursor, (hydroxy) hemopyrrol, because their
tissues are apparently too contaminated with porfyrins and
other pyrroles, and subsequently excrete these directly.
These are the so-called ‘evening-excreters’. In these people
there is a peak within a few hours after the evening meal.
They excrete relatively few in the morning and have the
highest value in the evening urine, two hours after the
hot meal. Evening-excreters often have a high score on
the HPU-questionnaire, but a surprisingly low value in
a normal HPU-test®. This problem can be overcome by
collecting the urine during 24 hours, or by taking a sample
of the urine collected after the evening meal up to and
including the morning urine. The people that primarily
excrete in the evening or during the day are generally very
ill and suffer of chronic fatigue. In people with an elevated excretion fatigue is a frequent problem. Nine out of ten
indicated that they suffer of regular fatigue.
Until now nobody has been found with the excretion
of a hexa- or hepta-HPL-complex. With however tetrapyrroles,
and that is strange. These are also people that
have a low score on the urine test, but have a high score
on the HPU-questionnaire. For this group a simple trick
can be used: freezing the urine for a short period. At a
certain temperature, the tetrapyrrol-complex disintegrates to monopyrroles. We subsequently do not measure the
HPL-complex then, but these monopyrroles and notice an
elevated value. This phenomenon probably rarely occurs.
Some illnesses and situations may lead to ‘false-positive’
values."
The information and the HPU-questionnaire on Keacs pages on HPU(http://www.hputest.nl/english.htm) have been of very good help for me. You can without a problem send a test to them to see if it turns out different.