|   What to do, if the VHC-Reader shows a “DATE” error?

The RFID card, that comes with each VHC Vitamin-D Test kit box, is providing the VHC-Reader with LOT specific data, such as the calibration curve, the required incubation time until quantification in Timer-Mode, and the EXPIRY date (Month/Year). The EXPIRY date of the LOT is compared with the internal date setting of the VHC-Reader, right after data transfer.
If this comparison shows the LOT has reached or passed its EXPIRY, the display will show  the “DATE” error and the VHC-Reader will thus refuse to perform the test.

  • If the internal clock of the VHC-Reader is set not set accurately, the “DATE” error might show up allthough the EXPIRY was not reached.
  • In this case, please check the internal of the VHC-Reader. Make sure it is set to a date upfront the EXPIRY date imprinted on the LOT specific RFID card and reinitiate quantification.


  |   What about the daily dosage recommendation for Vitamin D that are printed on Vitamin D supplements?

On most vitamin D supplements you will find a dosage recommendation of 1.000 or 2.000 I.U. vitamin D. This is a general recommendation based on (somewhat scientifically outdated) recommendation for the general population in case there is no evidence of vitamin D deficiency.

However, if your vitamin D consultant/therapist has performed an VHC Vitamin-D Test and the result shows that your vitamin D is not at an adequate level and needs to be adjusted, there obviously is evidence of vitamin D deficiency in your case. Based on your body weight he/she can calculate the amount of vitamin D required to rise your blood level from the current to an adequate level. In many cases this adjustment will require an additional amount of 100.000 I.U. vitamin D or even a multiple of that. Obviously, just the standard dosage recommendation as printed on the product is completely inadequate to fill this gap. Thus, he/she might recommend you a daily dosage between 5.000 and 10.000 I.U. per day. This is completely safe due to the fact that this recommendation is based on a previous vitamin D measurement and calculated to fill just the gap between your current and an adequate blood level. Also, a daily vitamin D shot of 10.000 I.U. vitamin D is completely normal for your body as this is just the amount that you would produce yourself in your skin during a normal daily sun exposure.

  |   Does the VHC Vitamin-D test need to be performed immediately after blood sampling?

The capillary of the UniSampler is not treated with any substance that would prevent coagulation of the blood sample. Thus it is important to deplete the blood sample from the capillary immediately after the sample was taken into the SampleBuffer. Once the blood sample is mixed with the buffer, the Vitamin D is immediately released and keeps stable for an extended period. You may thus collect several blood samples and prepare the pre-mix in the UniSampler, but you can delay running the tests and perform them at a later stage during the day,, if this is more convenient for your setup.

  |   Why is the skin not able to produce Vitamin D during winter?

In the northern hemisphere during wintertime the angle between the sunlight approaching the earth and its atmosphere is at a much lower level than during the summer season. Under this conditions, part of the sunlight that can pass the atmosphere during summer is reflected by the atmosphere and thus never reaches the ground. Unfortunately this includes the UV wave lengths between 290 and 315 nm, required to produce vitamin D in our skin. As a result our body has no option to refill its blood vitamin D level on its own between late autumn and mid spring. Thus, most people (according to studies 80% of the population in Germany) require additional vitamin D supplementation during this period in order to prevent their blood levels from becoming deficient in vitamin D.

  |   Why do certain skin care products have negative effects on Vitamin D production in the skin?

In order to produce vitamin in our skin we require direct exposure to UV light of a wavelength between 290 and 315 nm. Unfortunately these wavelengths are quite effectively blocked by current sun screen products. Applying sun screen with a protection factor of 10 or above will completely block your skins ability to produce vitamin D. Vitamin D production may even be blocked by many standard skin care products as many of them contain sun screen as standard ingredient to prevent skin ageing.

In order to enable your body to produce at least part of the required vitamin D in a natural way in summer you should thus not immediately apply sun screen whenever you go out between late in the morning or mid afternoon. Depending on your skin type your body has its own sun protection mechanisms and it may well tolerate unprotected sunlight for a certain amount of time every day without being damaged. You may ask your vitamin D consultant/therapist to estimate the safe self-protection time of your skin, based on your individual skin type and the local UV index of your area. Your skin health and it’s own vitamin d production capability will very much benefit if you apply any sun screen only after you have exceeded your individual local sun self-protection time every day.

In fact our skin itself requires high amounts of vitamin d for full activation of its internal sun damage prevention systems. Quite interestingly is the astonishing fact that dangerous forms of skin cancer in most cases show up in the skin areas with no or just minimum sun exposure, but not on the sun exposed, actively vitamin D producing areas. There is growing evidence that this is most likely connected to the activation of the skins immune and self-protection system by vitamin D.

  |   What is the reason that in the past only a Vitamin D blood concentration below 20 ng/ml was regarded as critical?

Vitamin D was initially identified in connection with the finding that cod-liver oil was found to be preventive and an effective treatment against a rickets, a childhood disease characterised by weak, soft and deformed bones. Further research revealed that UV-treatment had the same effect.

Rickets was found to develop only at Vitamin D levels below 20 ng/ml and initially low vitamin D was believed to be connected only with issues in bone formation in young children and elderly people. The idea that a Vitamin D level of 20 ng/ml may already be regarded as sufficient and does not require treatment is still widespread in part of the medical community and even some standard laboratory reporting.

In the last two decades medical studies and scientific research were able two proof that our body requires much higher blood vitamin d levels to keep all vitamin D dependant processes activated at an appropriate level . To dates common understanding of all vitamin d experts that regardless of age our body requires a vitamin d blood level of at least 40 ng/ml.

This message is spreading more and more in the last few years, due to intense activities of vitamin D experts and people, who have experienced how the adjustment of their own vitamin D level has improved their quality of life.


  |   What may be the reason that the VHC-Reader shows “INVALID”, if I start testing?

In the process of quantification, the VHC-Reader is checking the intensity of the c(ontrol) line, that is implemented as in process control for accurate performance of the lateral flow in the test cassette.

If the C line is blurred or does not show up with a defined minimum intensity, there is some issue with the test performance and thus the VHC-Reader regards the test as INVALID and thus it is not quantified.

  • Please make sure that you did not accidentally switched the VHC-Reader to Direct-Mode instead of a Timer-Mode. If this is the case, the VHC-Reader performed an immediate measurement instead of initiating the 15 minutes countdown. As the control line is showing up only several minutes after the test has started, there is no control line at this stage and thus the VHC-Reader came up with this error.
  • This error may also show up, if the cassette was accidentally placed in the wrong orientation in the adaptor, as the test line is usually much weaker than the intensity expected for the control line. If this is the case, please place the cassette in the right orientation in the adaptor and perform a measurement in Direct Mode.
  • If the cassette was run for the full 15 minutes, but the control line remains weak and there is some general reddish staining remaining on the strip, the reason is most likely that the volume of the pre-mix entering the strip was not sufficient to keep the lateral flow in the cassette active for the full 15 minutes. In this case the test must be discarded and repeated. Please take a picture of this cassette and it’s pouch with the LOT number and contact our support, describing the issue. You will receive a replacement for this cassette.
  • If the control line is weak or blurred, but the background of the strip is clean and almost white, there is most likely an issue with the test strip. The reason might be, that the cassette was exposed to temperatures of above 40 degrees Celsius during storage or transportation, leading to a heat degradation of the antibodies on the strip. As the chemicals and antibodies are sensitive to moisture, this might also happen, if the pouch of the cassette was accidentally damaged during production, transport or storage or the cassette was taken out of the pouch for several hours before performing the test. In any case the test must be discarded and repeated. Please take a picture of this cassette and it’s pouch with the LOT number and contact our support, describing the issue. You will receive a replacement for this cassette.

  |   What is the minimum Vitamin D blood level required for preventative activity?

Vitamin D levels below 20 ng/ml are regarded as critical low to maintain such important body functions as bone growth and regeneration. However many gene activation processes of vitamin D require much higher levels than that. Based on numerous medical studies and scientific publication most experts recommend a level of at least 40 ng/ml as it was shown that at or above this level vitamin is showing preventative effects. A second hint, that 40 ng/ml should be the minimum level for good vitamin D supply is the fact that vitamin D is only showing up in the milk of breast-feading women, if the level is above 40 ng/ml. Vitamin D associations usually recommended to achieve a vitamin D level of 40-60 ng/ml for the general public. For special purposes, e.g. to promote bone regeneration after surgery or to maximise physical power and endurance even higher vitamin D levels between 80 and 100 ng/ml seem to have optimal effects.

  |   How does your blood Vitamin D level effect your bodies general requirements for vitamins and micronutrients?

If your blood vitamin D level is rising, this will switch on the capability of your body to activate numerous genes, many of them producing proteins that require vitamins or minerals or other micronutrients for their activity. As a result, your requirements and consumptions of vitamins, minerals and micronutrients in general will rise and you should make sure sufficient supply by either your diet or supplementation to avoid any imbalances.

Special care should be taken on sufficient supply of Magnesium and vitamin B2, as both of them are required by the proteins activating vitamin D in your body.



  |   What is the half-time of Vitamin D levels if supplementation is discontinued or self production in the skin is diabled?

Our bodies vitamin D consumption is closely connected to its general availability in the body. The more vitamin D we have in our blood, the more active we are and thus the more vitamin D we require to be supplied to our body in order to maintain a certain activity level. Once daily vitamin D production in the skin is decreasing rapidly (such as in autumn) and/or daily supplementation is discontinued, blood vitamin D levels usually decrease quite rapidly. The halftime of vitamin D is only about 19 days and thus even the people who were able to build a good vitamin D level during summer may face vitamin D deficiency in winter.

As always there are individual differences, both in the ability to build up vitamin D in the skin during the summer period as well as in the individual vitamin D level during the winter period. In general and without supplementation about 50% of the population in Germany is vitamin D deficient even during the summer period. The level of vitamin D deficiency is rising to 80% during the winter period.


  |   Why did Vitamin D become such a central regulator during evolution?

The fact that part of the vitamin D activation is a process dependant on the availability and amount of UVB radiation in the range between 290-315 nm, has been used by nature since the early stages of evolution as tool to regulate all kind of gen activation processes connected with activity, energy uptake, growth, reproduction, but also protection. Algae started using it to estimate whether it makes sense to initiate the production all molecules required for photosynthesis’s and when to switch on the production of DNA repair and other proteins required to protect the cells from damage due to too high sun radiation.

Initially established in single cell photo- and phytoplankton the use of vitamin D as sensor and – once activated – powerful steroid hormone, has been maintained as a central „switch“ and is effecting the activity of several hundred genes in the human body. Just as in the primitive organisms it continues to regulate general activity, growth, regeneration and reproduction. Sufficient vitamin D supply is important through our whole live span. It has shown to have preventative effects against various common chronic, potential live threatening chronic diseases, associated to the industrialised society and its live style. Low vitamin D may even have negative effects on our mood and over time our mental health.

  |   How to use the VHC Vitamin-D Test to identify the individual maintainance dosage required to keep Vitamin D at an optimal level?

Based on a recent VHC Vitamin D test result, the blood vitamin D level you want to achieve level r maintain, your body weight and some additional personal parameters, your vitamin D consultant/therapist is able to estimate your individual daily vitamin D requirements. However, this first assumption might need to be adjusted due to you bodies individual ability resort and activate vitamin D provided as a supplement. He/she might thus recommend you to come back after about 2 months in order to run a second VHC Vitamin-D test and use its result to either confirm or readjust your daily supplementation recommendation for vitamin D.

  |   How to prevent potential Vitamin D overdosage effects?

If you have checked your blood vitamin D level with e.g. the VHC Vitamin-D Test your consultant/therapist is able to adjust his recommendations for individual vitamin D supplementation without any risk, even if he/she recommends a higher daily supplementation than what is printed on the product or the package insert. In general, Even long term vitamin D supplementation of up to 10.000 I.U. vitamin D per day are regarded as save, because this is just about the amount of vitamin D your body might produce on its own provided, there is sufficient skin exposition to sunlight containing the appropriate UV wavelengths during the summer period in the northern hemisphere.


  |   How often should I check my Vitamin D blood level?

There is two different situations, in regard too this questions:

a) You have been diagnosed with a low Vitamin D blood level and have started to fill up your vitamin D with supplement intake according to the advise of a vitamin D specialist:

If you alter your bodies daily uptake or production of vitamin D to a higher level than before, your blood vitamin D level is showing daily fluctuations for up too about two months until it stabilises again. Right after the first activation step in the liver, vitamin D blood levels will rise, but then lower again, because it is adsorbed by the cells of you body filling up their internal vitamin D storages for immediate requirements. Also, you fat cell will deplete part of the vitamin D in the blood and fill up your long-term vitamin D storage. It may take up to two months, until this process reaches a new steady stake again. Thus you should wait for this period to reevaluate the success of your attempt to rise your blood vitamin D level to a higher level than before and to decide on whether you need to fill up more or you may continue with a supplementation sufficient to maintain the vitamin D blood level achieved,

b) Your daily vitamin D supplementation is stable and changes in overall vitamin D blood level are mainly caused by seasonal changes of vitamin D production in your skin:

You should check you blood vitamin D level at least two times per year in autumn and spring in order to decide on whether your body would benefit from additional vitamin D supplementation.