UKH

I used to get 12.5 microgram Vitamin D tablets for when I'm not out in the UV light in darker months. Now it seems only to be available from Morrisons or other supermarkets at 25 micrograms. Does anyone know why this is? 

Is the larger dosage going to be too much?

I'm tending not to take the larger version as frequently.

Will not be too much.  I micro gram is 40 IU, you have been on 500.  Double that is nothing and still not very effective.

https://pubmed.ncbi.nlm.nih.gov/36983963/

I used to take 25 micrograms, now 50 but not necessarily every day, in conjunction with K2 (MK-7), which is supposed to keep calcium out of your arteries and put it into bone. I have mild osteopenia and hope this helps - nothing has broken recently. Safe dose of D is considered to be at least 5 times greater. I don't supplement when the sun is shining properly.

I’ve been on 50mcg (2000 IU) for a decade. I’m still here and haven’t broken any bones, except a metatarsal (but a lump hammer was involved in that)

I fractured L1 bouldering  last year and once discharged, GP did a FRAX score resulting in a bone density scan. I expected all to be good. Oh dear, although hips were ok, my lumbar region showed some osteopenia. Looks like the severity of the injury may have been exacerbated by it. Talking to GP, decades of nights may not have helped, irrelevant of me going out regularly throughout the year.

I'm now on bisphosphates and CalciD, 1000IU. You can't really OD on vitamins, it would be very unusual. If you don't need it, you're simply wasting money. I would say take it, but that's because I really was not expecting an issue.

My dose currently is 25 micrograms (1000IU). Been alot higher in the past to get my blood level raised.

One question is why you are taking vit d. If because everyone is recommended to take a small dose over the darker months by the NHS, then keep well within the range given by the NHS and/or consult your GP. If for some medical need then you will need to adjust the dose to meet the need to increase the blood level.

If you are interested in getting a blood test I have always used an NHS lab - https://www.vitamindtest.org.uk/ . You are not likely to get an NHS test IME unless showing deficiency symptoms. You could still be sub optimal though.

Have a look at the NHS comments on doses here - https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/ .

Except vitamin A.  But you have to really like carrot juice and you do get the visible warning of turning orange!  Or polar bear liver, but there are additional health risks involved in obtaining it.

I recall as a child being cautioned against eating polar bear liver, on account of the massive amounts of Vitamin A stored within.

So far avoiding it hasn't been a hardship.

Turning orange is a very visible warning to us all.  

Eating bears was a contribution to the demise of the Andree balloon expedition in Svalbard but it was the parasites wot dun it.  Apart from the fact it would be decades before anyone even knew of the existence of the island they were on (Kvitøya)

Water soluble vitamins will just piss out if you take too much. Fat soluble ones (A, D, E, K)  will be stored in body tissues and could potentially be harmful if taken in too large quantities for extended periods of time.

I usually supplement D in winter, but not this year as I found my levels were slightly too high in my last set of bloods. I do Thriva tests a couple of times a year. Mostly to keep track of cholesterol and testosterone, but a few vits too. I find it useful. 

Vit D levels slightly too high

What is too high?

Thank you all for your replies. In reading articles linked from the replies, it seems that there is an overall ambiguity about dosages of Vitamin D, when different sources are considered.

Certainly, hypervitaminosis A is something vets see occasionally in cats, hooked on eating liver (from whatever species). I remember such a cat, over 25 years ago, whose spine, on radiographs, was shown to be almost totally fused from the cervical/neck region, to the lumbar spinal/low back area.

I don’t think it’s too personal to share this…. 
The dark green is considered optimal. Light green in either direction, good but not optimal and so on. Not sure if the figures are general or specific to a 45 year old male, but should give a general idea. 

Thanks.  You certainly have nothing to worry about in the low vit D stakes, I can see that.

 In reply to lowersharpnose:

I suspect you could get many answers to that question depending on who is asked as to my knowledge there has been no definitive agreement of blood level of vit d even for deficiency.

However, NHS/NICE guidance talks about “adequate” for determining if any intervention is needed from their side. “Adequate” is above 50 nmol/L (25-hydroxyvitamin D concentrations (a marker of vitamin D status)). The interpretation of results that accompany the blood test result if tested by the NHS lab in the link I gave above are below:

Severe Deficiency - Below 15 nmol/L

Deficiency - 15 to 30 nmol/L

Insufficiency - 30.1 to 50 nmol/L

Adequate - 50.1 to 220 nmol/L

Risk Of Toxicity - Above 220 nmol/L.

Interesting to see ChrisBrooke‘s testing table. Personally from past research I have aimed to keep my blood vit d in an 80 - 120 range which is very similar to the dark green shown. However, it is personal and may not be appropriate for others. See your GP for advice as necessary.

Do the labs all use the same assay/protocol for Vitamin D testing? Otherwise which has the better specificity and sensitivity?

No knowledge of that, sorry.

No. NHS labs will have tendered and procured analysers from a number of suppliers (Roche, Siemens, Abbot, Beckman etc). They will therefore be tied into that suppliers assays, usually a managed contract. That trust/network will not be able to go elsewhere even if a.n.other supplier releases a demonstrably better assay, unlike a few years ago.

Vit D assays are not easy. The gold standard is liquid chromatography/mass spectroscopy. No NHS will use this due to time/cost restraints; immunoassay using chemiluminescence is used. The other issue is what are you measuring and how do you asses it? Most assays will pick up total vit D with ~100% D2 and D3. All decent laboratories will be part of an external quality assurance scheme for any assay. If you take glucose for example, it's easy, there's a a certified reference material. There isn't for vit D. Most EQA schemes use human serum  to send out blind samples for assessment and the labs report back. But most human sera will be unsuplemmented, so is it accurately assessing the process i.e D2 and D3? Good laboratories will play a part in this, but you could equally argue it's driven by the big companies.