Vitamin D - or not

Reputable websites such as Patient UK and Arthritis Research UK recommend that PMR sufferers take vitamin D. Also, research has indicated that vitamin D deficiency can exacerbate PMR symptoms.

However, the new PMRGCAuk website says the nightshade family (tomatoes, aubergines, peppers etc) "...contain solanine, which has a high concentration of vitamin D3. In excess, D3 may cause inflammation, muscle spasms, pain and stiffness."

So, I am confused. If anyone can clarify this apparent contradiction I would be grateful.


25 Replies

  • Hi there! It's not a contradiction really, although it may seem confusing. Some people think it is worth avoiding the foods from the nightshade family because of this observed characteristic. However, the key phrase is 'in excess'. There is very little firm scientific evidence about any dietary influences on PMR, particularly how much in the way of tomatoes, aubergines and spuds you would have to eat for it to make any difference. But there is evidence that many, perhaps even the majority, of older people in the UK are deficient in Vitamin D, which helps to protect your bones. Personally, and I do mean personally, I am on the side of the bones here, and believe that taking a vitamin D supplement while on steroids was a good thing for me to do. The dangers of Vitamin D deficiency are far greater than the risk of overdosing on it. Remember that the inflammation of PMR is caused by an autoimmune illness, not what you are eating or not eating.

    The PMRGCAuk website mentions the nightshades because we do have members who say that they find an anti-inflammatory diet does help them and we feel that people should share their experience. But we do say a) that there is very little scientific evidence to support any claims about it and b) that nobody really knows how much 'in excess' means. Most of the concentration of solanine in these plants is in the leaves and stems, with a much lower concentration in the fruits and tubers (e.g. potatoes). They are also high in anti-oxidants, that can actually be anti-inflammatory.

  • Thanks Kate.

    Anything in this plant family in moderation is probably OK then. I do remember I was eating about 10 tomatoes a day for a few weeks (we grew a glut of them!) prior to appearance of my PMR symptoms - maybe excessive - although this could have been coincidental. I agree it is autoimmune rather than what we eat but maybe the excess of tomatoes made the inflammation worse.

    It could be the cholinesterase inhibitors on this family that cause the pain and spasms in some people rather than the vitamin D according to some research.

    I will continue to take my vitamin D then.

  • I eat vast amounts of tomatoes, aubergines and peppers (also nightshades) compared to the normal UK diet - and raw which leaves the solanine, cooking approximately halves it. At one point when the PMR was really bad I spent several months on "no nightshades" to see if it helped. All it did was make my diet seriously boring! And now, when I feel extremely well I'm back to eating loads of them. It was a similar case with gluten - I was eating gluten-free near enough when the PMR got seriously bad and it seems to make no difference. I avoid wheat like the plague as I'm allergic to it anyway but it has more effects than anything else - too much carb definitely doesn't do me any good.

    Kate comments "there is evidence that many, perhaps even the majority, of older people in the UK are deficient in Vitamin D". It is by no means only the "older" generation although the elderly in residential care in particular are almost all severely deficient and this almost certainly contributes to falls - better vit D levels mean better muscle function too. Southampton has reported on high rates of children with vit D deficiency and demonstrating bone problems including rickets and on the east coast of the US a high proportion of young people in the 20s/30s were found in a study to be deficient.

    I live only just north of Turin, the touted latitude south of which one would be able to be replete in vit D just from sun exposure. Our regional osteoporosis expert reckons more than 95% of the population is deficient - and believe me, very few people use suncream (which does make a big difference) and in the summer everyone is outdoors as much as possible. If WE can't manage it - the UK hasn't a hope in Hades!

  • So true about those in the UK being deficient. Especially in the winter. It seems to make sense to get as much from food as possible even if that includes the nightshade family!

    I was just confused about the website saying there is a school of thought that vitamin D could cause inflammation when all the signs point to the opposite.

  • Yes, I realise what you mean. But we get less than 10% of what we need (even at a conservative estimate) from food - diet doesn't actually make a lot of difference unfortunately. Unless you eat well over half a pound of wild salmon every day together with a pound of mushrooms! The so-called fortified foods are of little value in the UK - when they say foods are fortified with vit D it usually means in the USA not here. Margarine is fortified - to bring it up to the same level as butter, not to make it a good source.

  • Hi again

    You have really set things going in PMRGCAuk-land today! We've been doing research to get back to our original sources and because we couldn't find any scientific evidence of tomatoes, aubergines, peppers and potatoes being harmful, the text on the website has been changed. Thanks for alerting us to this potentially confusing little snippet!

  • On this interesting topic, has anyone else read any of the reports advising leaving shop-bought mushrooms in the sun for half an hour from Spring to Summer before using to enhance their Vit D properties? You might be interested in reading the following:

    "Mushrooms can provide as much vitamin D as supplements - but only if you put them in the sun before you eat them.

    Mushrooms transform UV light into vitamin D

    Sun-exposed mushrooms are as effective at boosting and maintaining vitamin D levels as supplements are.

    They have to be in summer sun for 60 minutes to produce vitamin D - cooking doesn't reduce the vitamin level.

    Mushrooms exposed to the sun can provide as much vitamin D as a health supplement, a study has found.

    Researchers recommend people take the fungi out of their wrapping and leave them outside for half an hour before eating.

    Much like our skin, mushrooms transform ultraviolet light from the sun into the vitamin and continue to do so even after they have been harvested.

    Eating mushrooms could provide as much vitamin D as swallowing a supplement - but you need to put them in the sun first

    The nutrient is essential for the immune system, strong healthy bones and teeth and the absorption of calcium.

    In the study, 30 adults were given a daily capsule for 12 weeks containing either 2,000 units of vitamin D, or sun-exposed mushroom powder with high-levels of the nutrient.

    At the end of the trial, there was no significant difference in the participants’ vitamin D levels.

    'These results provide evidence that ingesting mushrooms which have been exposed to ultraviolet light and contain vitamin D2, are a good source of vitamin D that can improve the vitamin D status of healthy adults".

  • That's really interesting Celtic! Thanks for sharing

  • Hi Kate,

    That's excellent! I do like to see things backed up with scientific evidence and so far could only find evidence of adverse effects on rats and livestock of the type of D3 produced by feeding on nightshades. This is probably the same 1993 paper as mentioned on the site.

  • Please can anyone tell me the difference between Vit D2 and Vit D3?

  • Hello corralie. Vitamin D2 or ergocalciferol is plant derived and D3 or cholecalciferol is the type we produce in our bodies by the action of sunlight. D3 supplements have been found to be far more effective than D2. There is a useful paper explaining it here:

  • Thank you Badgergirl - I'll have a look at the nutrition website.

  • Hi all,

    On the subject of vitamin D and it's benefits - as well as eating mushrooms at least 3 times a week, and having fortified olive oil based margarine because of my lactose intolerance, I have taken a multi vit pill since developing PMR which contains a good amount of vitamin D. I also have 1000mg of calcium each day.

    Last week I had my DEXA scan. It is 3 years since I had the first one which showed bone density of about 87% - very high in the green band. As you can imagine, I was some what worried about the outcome of my latest test - surely 3+ years on steroids must have taken quite a toll?

    I was hanging over the nurse's shoulder to see the state of my hips etc. 'Perfect' she said, 'Your bones are as good as ever.' The results looked the same as they were 3 years ago. I could hardly believe it.

    We then spend some time discussing the reasons 'why?' and she put my bone health down to 3 major reasons - a healthy diet with lots of greens, plenty of calcium and vitamin D and, because I live in a three storey house, a great deal of 'weight bearing' exercise due to continually climbing stairs, often carrying 'stuff'.

    I will continue to climb my stairs gratefully and hope that one day, I can speed up them 2 at a time as I did before my illness.


  • I do a lot of walking but carrying stuff is difficult. I always get a flare after carrying shopping, even light stuff!

  • Hi Badgergirl,

    Don't worry - it's climbing the stairs that matters, because everytime you make that extra step you are lifting your whole body weight and, even if you're slim, that's a lot for you to carry. Coming down, with each step there's a jarring effect on your skeleton. Both these manoeuvers create stress on your skeleton and, therefore, increase bone strength.

    We are being advised nowadays, to use the stairs in shops etc, rather than lifts and elevators. It is believed that bone density will be increased by doing so.

    As I have begun to recover from PMR, I am walking more to the shops and carrying moderate amounts of shopping home. I still suffer the next day if I do too much, but I think it's because I am not as fit as I was pre PMR. I rest up for a day and then I'm OK.

    3.5 years on, after 2 flares which put me up to 30mg of pred, I feel that, at last, I'm on the home stretch. My main prob now is getting my head around the fact that I'm not an invalid anymore, and it's quite hard to do - I'm not brave now like I used to be, but, hopefully, I'm not too old to recover.

    All the best,


  • You're never too old to recover Pats! It probably takes time for the confidence to come back when we are so used to being invalids.

  • The test for Vit D deficiency is an exclusion test made before PMR is diagnosed.

    Vit D deficiency presents with aches and pains.

    If found to be deficient pure Vit D should be prescribed, 'Dekristol (brand name made in Germany) at the rate of 20,000 units twice a day until the correct level is reached.

    Thereafter a minimum daily maintenance dose of 1000 units per day. These can be purchased from reputable chemists (make sure they are made in the UK or European Countries) and cost £5 for 90 tablets at Boots. Do not buy over the net.

    Follow this link and read up on it, this site is run by two GPs and is used by Medics as well as patients.

    Read a patients experience on this link:

  • Hi sambucca. Clicking on the first link said 'page not found'. Was it this one?

  • Hi Badgergirl,

    I cannot eat peppers as they do make me more achy, but tomatoes and potatoes - no problems, but I think the secret lies in the amounts that we eat and our own tolerance levels.

    I always leave the skins on potatoes except when mashing.


  • I agree pats. We're all different and the amount we eat is a likely factor. I knew a guy once who ate chilli peppers all day like sweets and he had terribly painful rheumatoid arthritis - probably from the excess - yet in small amount chilli is an effective anti-inflammatory and painkiller.

  • Hi Badgergirl,

    Well, I didn't know that chilli can be an helpful in small amounts - I must try it.

    Thanks for the advice.


  • Here's an interesting article about chilli and pain:

  • Badgergirl, the whole article is re-printed with permission, in the Autumn/Winter Newsletter 2011, on page 7. The link is also printed on that page at the end of the article.

    It was a follow up article a patients experience with Vit D deficiency which is in two previous Newsletter. I cannot block and copy it, although it is available to download.

    Let me know if it works. .

  • Hi sambucca. Yes it does, thanks.

  • I found pats comments interesting!

    I too had a dexascan done about 3 months after I first took 15mg/day pred as a sort of baseline. It was done in Durham on a somewhat elderly machine but it was fine - a tiny bit of osteopenia in a vertebra. Last spring I had another, this time in northern Italy, after being on variable levels of pred, mostly well over 10mg, for three and a half years. To all intents and purposes it was identical (you can't actually compare results from different machines, even the same model). Same vertebra, same osteopenia, otherwise nothing of note. No alendronic acid, calcium and vit D every day religiously - and actually for nearly a year almost no exercise, it being a bit difficult to do much when on crutches!

    I, too, wondered aloud on another forum about 3 or 4 years ago about using the stairs as anti-osteoporitic therapy! For exactly the same reasons as pats mentioned - and when you have PMR the toddler technique we have to use doing the stairs increases the shock on the skeleton that stimulates it to build bone. So when the weather is bad - use the stairs! I was unable to go up more than about 3 or 4 stairs for some considerable time - so I suggested if you can't get up the stairs, at least catch the lift up and walk down :-)

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