"Toxic effects" of high vitamin D [ - Vieth, 2006]

Thread for Fungal Infection Trust members:

The actual one line quote is: "High doses of oral vitamin D supplements, however, have been shown to have toxic effects (Vieth, 2006)."

This followed a ( - clearly questionable?) view on the safety (for ALL?) of vitamin D formed by sun-exposure:

"The cutaneous conversion of 7-dehydrocholesterol to previtamin D3, which spontaneously isomerizes to cholecalciferol, is regulated so that prolonged sunlight exposure does not lead to excess production; both precholecalciferol and cholecalciferol can be photolysed to inert compounds."

[ - does that apply to ALL, . . . . . . withOUT qualification ? ? ? See below !]

The above from paragraph 30 on p. 11 of "Update on Vitamin D Position statement by the Scientific Advisory Committee on Nutrition" of 2007 - SACN report available FREE online online ( - hurray !):


As we know from other posts on this forum, there are (seemingly ?) credible and significant reports of well over a decade of a sub-group of the population, which is affected by or exhibit a "vitamin D dysfunction" found in those with a range of medical conditions: for this group, it might be said that even limited amounts of sun exposure can further elevate the already (relatively) higher calcitriol levels, which inflame an already poor situation further, unlike in their healthy counterparts, aggravating the (often unidentified) disease process ! These are said to be or include Th1 inflammation causing conditions. This knowledge is POWER ( - I dare say !) for those so affected !

I remain unsure whether Prof Vieth even adequately ( -or at all) acknowledges the existence of this sub-group, the size of which, I fear may be increasing, year by year as the number of people with this dysfunction rises ! The level of supplementation Vieth considers as safe would NOT appear to apply to this sub-group, for which one body of opinion recommends reducing calcidiol, or 25(OH)D levels . . . . . and hence ANY supplementation would be seen as counter-indicated ! A HIGH vitamin D level, as assessed by the standard calcidiol [ - or 25(OH)D] blood test, for this SUB-GROUP would, it seems to be at levels considered low ( - either as inadequate/insufficient or deficient) for those in the portion of the population not so affected.

[As clear as . . . . . . . mud ? ? ? It is, it seems for most of the UK medical profession, sadly at present ! ! !].

Just ONE more viewpoint of this complex endo-immunological bio-landscape to consider !

Warm regards to all, on a sunny cold autumn afternoon,

Epictetus x

Sun 8 Nov 2015


Last edited by

5 Replies

  • So much to think about.

  • Yep, but hopefully . . . . . . forewarned is forearmed !

    Esp. on this issue of vit D in the UK, where I'm finding UK Drs completely unaware of the known "vitamin D dysfunction" which occurs in a range of conditions, . . . . . . INCLUDING fungal issues, it is said !

    TC - one calm breath & one calm step at a time !

  • Epictetus, long complicated name for me to remember how to spell but time I get to reply box! 

    I have found your post re Vit D, very very interesting! For several reasons! Years ago I used to sail off E coast a lot , so yes certainly had plenty of wind and sun exposure, not deliberate sunbathing at all.always using a sun factor lotion and covering up when and where necessary. I used to sunbathe when many years younger than now (almost 69). My working weekday life was in an office! 

    Anyway to the here and now, I developed Vitilgo 2 yrs ago, no colour left on arms at all. I look anemic really. I also have other health complications. But on the Vit D front, my doctor prescribes me a Monthly D3 100 000 U/l cholecalciferol dose. It's in a small ampoule I have break at both ends then pour into a 1\2 tumbler of water to drink. 

    Some other forums advocate quite strongly self supplementing with various Vits and Minerals sometimes. B12 being the most strongly advocated.

    Anyway one day I asked my Doctor and my pharmacist here, about supplementing extra VitD and they were both strongly adamant NO, I must not, but of course neither would say why, it was just NO!  

    I think perhaps the The liquid dose is a slow release? anyway  once a month is deemed sufficient. One thing I do know is that for 2/3 days after having it each month, I seem to feel perkier and better in myself, difficult to explain! Then that 'wellbeing" feeling gradually diminishes and I'm back to dealing with other health issues. 

    In fact I unilaterally stopped taking all prescribed meds except my Levothyroxine (one of those take for life things) and the D3,  and except for neural transmitter/receptor problems arising from a brain haemorrhage, can't really say I feel ill. 

    I'm one of those people living with conditions others often feel ill with and die of! I can't get any specific prognosis, only semi diagnoses, you have this or that, we don't know why, even when they know what, so I'm guessing there are blood tests they haven't even thought of doing yet on me. The initial treatments, which meant drug contraindications played  even worse havoc with my neuropathy, which I rightly or wrongly put down to affecting my liver and giving me cirrhosis. 

    I do know that what adversely affects the liver, also affects the bloodstream and eventually the brain. I will admit that one day I did buy a tub of Vit D supplements, took 1 only and within 24 hrs genuinely felt like death warmed up! So never again, I stick to the monthly prescribed D3, whether I need it not I don't know! 

    I do though always have a glass or two of either Orange juice Vit C enriched, or mixed fruit juice which says rich in Vitamins C, B6, B1, A and B9. Ive checked for other additives etc., which are no more, occasionally less than bio products and better than cheaper brands  of juice? The supermarket make of mixed juice I have here says its 81% minimum fruit, which seems quite high and good to me as far as percentages of genuine content go, in mass produced products!  also Vit C doen't sit in the body,  it passes out through the urinary tract relatively quickly compared to other drink and foodstuffs. 

    I don't seem to have had any Vit D tests in my bloods, but my B12 level last month was well over 900, 900 being at top end of range!  I don't supplement B12 at all, again I asked my pharmacist a week ago, he didn't have any in stock and wondered why I wanted it. Next time I go I'll take the blood test result with me! Thanks again for the Info you  posted. Sambs. 

  • You may like to keep up your investigations and ponderings . . . . . on this systems-wide prohormone in human biology.

    One further recent viewpoint is:


    Not sure how comfortable I'd feel about anyone taking 100,000IUs every month - seems like a HUGE dose for anyone.  However, can see it being particularly an issue for those in whom a chronic inflammation-causing illness, said to involve the known "vit D/VDR dysfunction" has not been properly ruled OUT !  Beware ! 

    A large dose will initially act as an immunosuppressant, before calcitriol levels eventually rise, . . . . it has been said, . . . . . with what seems to be quite convincing evidence for well over a decade !

    Best wishes,


  • epic ,Another interesting reply from you. I'm already immunosuppressed by way of not needing the TB jab as a teenager. Had a tb infected gland removed from neck  as a baby or toddler. No parents or grandparents left in family to expand on the only knowledge that it happened and scar still on my neck under chin. 

    Other known immunosuppressed condition is my Thyroid, diagnosed early last year as Hashimoto's. So both in area of the HPA axis. I do however get  various infections every so often and have had one form or another of bone deformity going on through the my life. I had to have 3 separate operations on my right foot between ages of 14/55. I also had an extremely high arch in that foot. 

    Whether that's another piece of the immuno suppressed  part of the jigsaŵ I don't know, neither do the Specialists, who all treat me as having only the condition they specialise in. Blood, Thyroid, Liver. No one checks on my fungal nail infection, and the toe joints on my left foot are now curling upwards, my own GP here I show my feet every so often when I have to go collect my 3monthly renewal prescription for Levo & D3. He's more interested in taking my blood pressure, temperature, weighing me  and listening to my breathing. Then it's a case of here's your prescriptions for the usual blood tests and for your Levo/D3, plus Spiriva for when I have the rare but occasional "I can't breathe episodes" or I can use once everŷ morning if I want to. I only believe in taking things when absolutely necessary. 

    I've tried OTC and prescribed treatment for the F N I, to no avail. 

    Well I'll check out your link now re the Vit D3. 

    Also donkeys yrs ago when still in UK and before my health showed any signs of complications, I bought the Readers Digest Guide to Vitamins, Minerals & Supplements - thinking it may come in handy one day! Albeit 1st edition was published in 2000, ah yes the year I was 1st diagnosed as being Hypothyroid! The Chief Consultants for the contents were a Dr Alan Lakin & Dr Ann Walker, involved in Food Chemistry & Human  Nutrition and both Lecturers at University of Reading respectively. The 3rd Consultant was a Dr John Cormack, senior partner in a General Practice in Essex and he was also Press Secretary for the BMA at the time. Where they all are now, I have no idea. 

    Yes there is a section on Vitamin D but no mention of D3. Vitamin D is supposed to help the immune system. Thanks for your replies before. 

You may also like...