Sample Tests

We check the service from start to finish buy sending samples from Jon - who tends to have a

low level. This gives a feel for turn round, shows the style of report you will receive and an

understanding of the types of results seen in the UK population including impact of


March 2024 Secret shopper: Jon Comments Jon reduced his dose of Vitamin D3 to 1 x 25 µg after he managed to get into the ‘Sufficient’ category. The March sample was delayed in the postal system for several weeks. When it finally arrived in the laboratory the turn round was 7 working days which is within the guideline offered by the laboratory. On the reduced supplementation Jon’s vitamin D level has fallen into the insufficient area. Jon will send another sample in June. February 2024 Secret shopper Jon Comments Jon is a 67 year old white male. In January his level was ‘Insufficient’ and this was with a daily dose of 2 x 25 µg D3. Jon increased his dose to 3 x 25 µg daily for 4 weeks and then repeated the test. This higher dose saw a level of 55 nmol/L. On 28th February he reduced the dose down to 1 x 25 µg/day. We will repeat the test in a month or so to see how this impacts levels. January 2024 - Turn Round and Levels Secret shopper Jon Comments: Jon has sent in 6 samples over the last few years. In January 2024 he had been taking 2 x 25 µg Boots Vitamin D High Strength tablets ‘most mornings’. It is surprising to find levels are not even up to the basic 50 nmol/L. Jon will try and remember to take 3 x tablets now every morning for 4 weeks and repeat the test in middle of February. May 2021 Secret Shopper: Jon A 64 year old who we reported on in February when his level was 70 nmol/L. Of that 40 nmol/L was due to D2 supplements. Comment: Turn round is a little longer than the laboratory target and the email with the results apologised for this, and explains that they are experiencing unprecedented demand due to additional Covid-19 related work. Hopefully turn round will come back down over the next week or so. Jonathan has not taken any Vitamin D2 supplements since 17th February and 61 days later the residual level of D2 = 14.9 nmol/L shows a long half life of a little over 30 days. Vitamin D is fat soluble and stays in the body stored in your fat a lot longer than water soluble vitamins. Remember that Vitamin D2 is usually undetectable unless you take it as a supplement. The 2.8 nmol/L on all the other Secret Shopper results is the limit of detection. March 2021 Secret Shopper: Jen A 31 year old specialist doctor in anaesthetics in south London. We tested her in December and she had a deficient result of just 23.4 nmol/L. Jen started a 4000 iu/day vitamin D tablet. We retested three months later when her vitamin D supplements should have have come to the ‘steady state’. Comment: Jen’s total vitamin D level is great now. Three months on 4000 iu of D3 supplements has brought a deficient level up to one that is reasonable. Jen herself has also noticed the troublesome acne she has suffered for years is receding. She ‘Googled it’ and points to yet another association with Vitamin D - a number of studies have reported this including a paper from 2016 here… It is likely that Jen has a genetic cause for a low vitamin D. Her father, Jonathan below, also has a very low level without supplements and one of Jen’s siblings - Rachael below, also has low levels without supplements. Turn Round: The sample took over a week to get from South London to the Birmingham laboratory. Unfortunately first class post from some parts of the country is very ‘lumpy’ at present - to borrow a phrase from Covid-19 press conferences! Secret Shopper Laura A 35 year old town planner living in the West Midlands. Takes 25 ug (1,000 IU) Boots ‘High Strength Vitamin D’ every day all though the year. Tested as her two sisters (Rachael and Jen) below and her father (Jonathan) all have naturally low vitamin D level. Comment: Considering the daily dose of supplements this is not a very high level. It is likely that Laura would be in the ‘Insufficiency’ category without supplements. We will retest her sister Jen later in March to see if supplements have sorted out her very low level from January. Turn Round: The laboratory has had machine issues and with lock-down servicing can take longer at present. The turn round at 14 working days was outside the laboratory target but the lab is working hard to get back on course. In the longer term an additional LC-MS/MS and extra staff are going to help keep up with continuing demand both for public testing and R&D studies. Secret shopper: Jonathan A 64 year old Clinical Scientist recently retired from the NHS and now working on T cell Covid-19 reactivity. The father of Jen and Rach below who both had low levels. We await the return of his third daughter’s result - she is 7 months pregnant so lets hope it comes back at a good level! Jonathan is known to run a low vitamin D unless he takes supplements. For Secret Shopper he kindly switched to D2 supplements in January, taking 6000 IU/day for 5 weeks before this test. The sample was taken two days after supplements were stopped. He had previously been taking 2000 IU/day of a D3 supplement. Comment: This is the first Secret Shopper with a measurable Vitamin-D2. All the others have been reported by the lab as 2.8 nmol/L which is simply the limit of detection of the method. While his total level is reasonable at 70 nmol/L the D3 alone would have given a low result. With two of his daughters having a low vitamin D as well one must consider a genetic link to this family tendency to low vitamin D. We will retest at the end of April to see if the D2 has all cleared and what his natural level of Vitamin D is. Turn round The lab time was 9 working days which is at the longer end of the turn round target. In February You Tube presenter Dr John Campbell used the test on his channel causing a surge in interest in the service from the general public. Things should be back to normal over the next few weeks. February 2021 Secret shopper: Rach A 37 year old hospital consultant living on the south coast with an outdoor lifestyle. The eldest sister of our DEFICIENT trainee anaesthetist Jen (see below - January secret shopper No. 1) Rach takes an oral supplement “when she remembers”. Comment Rach has a low level of Vitamin D just getting to the ‘INSUFFICIENT’ level. Not as low as her younger sister below ,who had a level of just 23.4 nmol/L. Not great when you consider she does take some D3 oral tablets sporadically, and also spends weekends doing lots of things outside. This is an interesting finding as these two sisters have a father who has been shown to have very low vitamin D levels over many years. He has changed to D2 oral supplements for a couple of months to see what his natural D3 level is these days. Remember Vitamin D3 is made by your skin as well as being in food/supplements. Vitamin D2 is only obtained from vegetable products and most people have an undetectable level. Rach and Jen have another sister - currently six months pregnant, and she will be our second secret shopper for February in a few days time. Turn Round The in-lab time of 5 working days is better than the ‘up to 10 working days’ lab target. However the laboratory saw huge demand for test packs towards the end of February which may impact on turn- round in early March. If you are missing a result do check your spam folders, as the automated system sending the emails is sometimes considered as spam by local systems. January 2021 No.3 Secret shopper: Karen A 61 year old Solihull resident who has kept strictly to lock-down rules over the last 10 months. Karen is aware of the interest in Vitamin D and possible severity of Covid-19 infection. She takes four oral supplements daily, two of which contain Vitamin D: Boots ‘High Strength Vitamin D3’ and Aldi ‘ Heart Health, Omega 3 fish oil’. Comment Karen has achieved the highest level of Vitamin D of all our secret shoppers to date. It is a level often seen in the laboratory and and such levels are associated with Vitamin D3 supplements being taken. The Boots tablet has 25 ug Vitamin D3 but the amount in the fish oil is not stated - but looks like it does the job! Do remember there are two oral supplements on the market. D3 comes from animal sources - often extracted from sheep’s wool. D2 is extracted from vegetable sources. The body also produces D3 in your skin due to UV light. Unless you take a Vitamin D2 supplement your D2 level is usually low. The 2.8 nmol/L you see in all the reports so far is actually the ‘detection limit’ of the method. We have an upcoming secret shopper who has switched from D3 to D2 supplements to demonstrate this. Please do not ‘do this at home’ though as D3 is thought to be better to supplement, unless advised otherwise by a health care professional. Turn round Karen posted her sample on a Sunday night in the reply paid first class post pack supplied. It arrived in the laboratory fast. Analysis was prompt with a turn round of 5 working days. The laboratory is to be complimented - the staff are working in very different ways with social distancing and face masks mandatory, and the workload is very high with NHS and research samples and our service to the public. January 2021 No. 2 Secret Shopper: Audrey An 89 year old great grandmother who after a stroke a year ago has been a care-home resident in the South-West. She takes a daily Vitamin D supplement, and has done so for many years. She has hardly been outside for over a year. Comment: Audrey’s daily supplements are clearly working well for her. She has achieved a level not only of over 50 nmol/L but also over 75 nmol/L, which is a level that many suggest we should all be aspiring to. She did better than Jen, the junior doctor below and one of her six grandchildren! Turn round: Considering the laboratory has had Christmas and New Year, not to mention special working for social distancing, the turn-round of 4 working days is exceptionally good.

January 2021 No. 1

Secret Shopper: Jen A 31 year old hospital doctor in London currently working extra shifts in the back of an ambulance helping transfer Covid-19 patients between ITUs. She is vegetarian and spends a lot of time outdoors. She does not take vitamin supplements.


Jen was surprised that she was deficient. She intends taking several 25 ug (1,000 IU) vitamin D3 tablets/day to get her level up. We have offered her a retest next month. Turn round: The service is hugely busy at present. Considering this sample arrived just two days before Christmas, a turn-round of 10 working days is pretty good. We have set up a second secret shopper in January to see how things are going.

December 2020

Secret Shopper: Chris Chris was our second secret shopper from November. He sent his sample back the same time as his wife, whose results are below. Unfortunately his spots were not very good and the laboratory was not happy to analyse them and sent Chris a free of charge pack to try again. Second time round his spots were just as bad - there was not enough blood to go right through the filter paper. So…… the laboratory kindly sent Chris a third test pack, again free of charge. This time Chris went the extra mile and there was enough blood on the card to analyse! Comments: Chris has a reasonable level of Vitamin D at 56.1 nmol/L. However he does take two daily supplements containing Vitamin D and he was a bit surprised it was not higher. The laboratory does not analyse samples that might give misleading results, but rather sends out a fresh pack if there are concerns about the blood spot appearance. This can be for samples that are insufficient, and also where it looks like there has been ‘overspotting’, that is several drops of blood placed on top of each other. Turn round - the return of the sample by first class post from Chris was reasonable considering it was the week before Christmas. The laboratory turned the result round in less than 3 working days which is excellent considering how busy they are with their work tripling over the last year due to concerns about getting Vitamin D levels right during the pandemic. November 2020 Secret Shoppers: Judith & Chris We have two secret shoppers this month. Judith and Christopher live together in Kent and are retired. They both take cod liver oil every day and also a multi-vitamin tablet. They put their samples in the post at the same time in separate pre-paid envelopes. Comments: Judith’s sample took over a week to arrive - the lab is experiencing some postal delays at present. Once in the laboratory the sample was analysed in 4 working days and reported back by email the same day. Considering the laboratory staff are all coping with the second lock-down and a huge growth in workload, this is extremely impressive. Judith has a good level of Vitamin D which would be expected from her long-term oral supplementation. Chris’s results have not come back yet which is not unusual. Chris and Judith’s samples may have been on separate runs, or the lab may have needed to reanalyse Chris’s sample as they wanted to check the result.

October 2020

Secret shopper: Sue Su is a 28 year old female engineer who has worked mainly from home in Birmingham since lock-down. She takes a 25ug (1,000 IU) tablet of Vitamin D3 daily. Comments: Su has an adequate level but without her supplement she would almost certainly have been in the