Calcium supplements do not prevent fractures
BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h4825 (Published 29 September 2015) Cite this as: BMJ 2015;351:h4825
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Having read the article and the ensuing correspondence, I for one am inclined to follow Professor Karl Michaelsson.
I wish we (the general public) could more readily receive INDIVIDUALISED advice - be it from one's own doctor or a dietitian, with full knowledge of the person's known medical, biochemical and radiological history plus dietetic peculiarities.
The steady leaching away of medical expertise and its replacement by cheap personnel gazing at protocols on computer screens, then pronouncing - is not a delightful prospect.
Competing interests: Ancient. Stuffed full of healthy , varied diet, and cod liver oil and vitamins A and D in childhood, burnt black by sunshine ( despite genetic melanosis of a mild degree). I get sun burnt on the Alps. No UV barriers ever.
Preventing fractures in the elderly with vitamin C.
For whatever it's worth
It is not easy to prevent all and any falls at any ages. everybody is prone to falling occasinally. What is important is to first know how to fall without seriously injuring oneself and how to keep the aging body to continue producing enough collagen.
Perhaps I may share my own experience.
This year I turned 80. I don’t feel my age except perhaps that I feel less steady on my feet. I still walk on high heels.
That’s why I look where I step (remembering my mother’s constant reminder “look under your feet and where you step”), I don’t rush, when I fall I always make sure that my arms are outstretched in front of me , so that I don’t fall on my face.
As a teenager I was in many sports, including training in gymnastics for the Olympics and fencing, and walk as much as possible and still do all my housework and work around the house.
Importantly, I take sufficient daily doses of vitamin C (sodium ascorbate) powder dissolved in a small glass of water with occasional glucosamine with chondroitin and magnesium and calcium supplements. I also take about half a teaspoon of white vinegar dissolved in 100ml of water, sipping it very slowly, after my meals.
Most of what I eat are vegetables (yes, even dried kale; why does everything good for you taste so vile) and fruit, with some eggs and meat, very little cheese.
When I occasionally fall, I don’t develop any bruising and don’t feel any pain. No broken bones.
How do I measure the effect of the above? By looking at my face so far without any wrinkles on my forehead and around my eyes and neck. I never used any makeup, and the only thing I use on my face, hands and feet is vaseline ( petroleum jelly).
Competing interests: No competing interests
BMJ Letter. Calcium and Vitamin D Supplements.
For those of us called to advise older people how best to keep healthy and active, Karl Michaelsson’s article is of limited help.1.,2.
It is accepted that there are increasing numbers of elderly people who suffer fractures with the significant morbidity and mortality these bring.3.
His analysis has a double warning. “Calcium products, with or without vitamin D do not protect older people from fractures.” Also he cautions against escalating promotion and doses of supplements for a higher proportion of elderly people.
However, two of his suggestions are of no practical help in the short run: “A large scale meta analysis of high quality trials” or “evaluate the effects of different dairy products.”
The Department of Health advises that people aged 65 years or over should take a mixed diet which is likely to contain all the vitamin D and calcium that most people require.4. Despite this they recommend a daily supplement containing 10 micrograms (0.01mg) of vitamin D if they have darker skin or are not exposed to much sunlight. Adults need 700mg of calcium a day and there is no general recommendation to take a supplement. There is a warning that taking more than 1,500mg a day as a supplement could cause abdominal pain and diarrhoea.
Medical advisors and the general public need a simple and sound way to identify those who are at risk of osteoporosis and fractures, and for whom supplementation may be valuable. Is this impossible?
Also clear guidance about the doses and duration of these supplements would be valuable. The current uncertainties only play into the hands of the purveyors of misinformation and the producers of the supplements.
William Cutting, retired consultant, counsellor on health and wellbeing of the elderly, Oxford.
1. Cutting WAM. Seniors, Make the Most of the Health You Have. Face the Future, Book 3. 2015; O&U, Leatherhead; ISBN:978-1-910197-13-4
2. Michaelsson K. Calcium supplements do not prevent fractures. BMJ 2015;351:h4825
3. Morris ME. Preventing falls in older people. BMJ 2012;345:10. [Ref.ID 93599]
4. NHS Choices http://www.nhs.uk/service-search
Competing interests: No competing interests
It is a pleasure to read this editorial and the two research articles “Calcium intake and bone mineral density: systematic review and meta-analysis [1], and "Calcium intake and risk of fracture: systematic review” [2], published online on the same date, with the same data sources and corresponding author; also the conclusion in both the research articles is more or less similar.
Although there are enough scientific literature available with regard to low bone mineral density (BMD), osteoporosis, calcium and vitamin D supplementation and bisphosphonates, this is a really good systematic review and meta-analysis with a clear evidence based result.
An earlier article by the author proved that bisphosphonates are the primary treatment in osteoporosis and adequate calcium and vitamin D is required in all patients with osteoporosis [3]; alone calcium and vitamin D supplementation is not effective in patients with osteoporosis but continue to be recommended despite evidence of lack of benefit [4].
To study the effect of calcium and vitamin D alone in patients with osteoporosis is not justifiable and not ethical at the present time.
We are thankful to the authors.
With regards,
References:
1- BMJ 2015;351:h4183
2- BMJ 2015;351:h4580
3- Maraka S, Kennel KA. Bisphosphonates for the prevention and treatment of osteoporosis. BMJ 2015;351:h3783
4- Grey A, Bolland M. Web of industry, advocacy, and academia in the management of osteoporosis. BMJ 205;351:h3170.
Competing interests: No competing interests
Please do not throw the baby out with the bathwater: I agree calcium supplements are not needed if one has a healthy diet, as your editorial summarizes (1), but vitamin D supplements might well be needed. My patients live in the climatically challenged Scotland, where most of us are deficient in vitamin D (2).
It is in early childhood that good bone health might be influenced by a good mineral rich diet and sunshine or vitamin D, it probably cannot be influenced much during the few years of a trial in later life.
However, we now know that sufficient vitamin D contributes to a healthy immune system. And even in later life, many divers conditions, as encountered by general practitioners, from Crohn’s disease (3) to surgical outcomes (4) or cancer survival (5,6), could be influenced by correcting vitamin D insufficiency, and this (baby) should not be ignored.
(1) Michaelsson K. Calcium supplements do not prevent fractures. BMJ 2015;351:h4825
(2) Food Standards Agency in Scotland. Vitamin D status of Scottish adults: Results from the 2010 & 2011 Scottish Health Surveys. Purdon G, et al. 2013
(3) Raftery T, et al. Effects of vitamin D supplementation on intestinal permeability, cathelicidin and disease markers in Crohn’s disease: Results from a randomised double-blind placebo-controlled study. United European Gastroenterology Journal 2015; 3(3):294–302
(4) Iglar PJ, Hogan KJ. Vitamin D status and surgical outcomes: a systematic review Patient Safety in Surgery 2015;9:14
(5) Wong et al. Vitamin D and cancer mortality in elderly women. BMC Cancer 2015;15:106
(6) Afzal S, et al. Genetically low vitamin D concentrations and increased mortality: mendelian randomisation analysis in three large cohorts. BMJ 2014;349:g6330
Competing interests: No competing interests
In her Editor's choice, Theodora Bloom queried: "Why then, asks Karl Michaëlsson in a linked editorial (doi:10.1136/bmj.h4825), do so many organisations continue to recommend intake of high levels of calcium and vitamin D that cannot be achieved by diet alone? The profitability of the global supplements industry might play a part, he speculates, noting how difficult it is to identify the influence of industry on people who write dietary recommendations.”
In part, the explanation is implicit from the devotee of a popular brew who declared: “I drink Guiness not because of its advertisements but because I know it is good for me”, and by a notorious propagandist who practised the truism: "If you tell a lie big enough and keep repeating it, people will eventually come to believe it."
Simple iteration still holds (What I say three times must be true"). Barefaced lying is frowned on by all right thinking scientists, when it is found out, but all must admire unconditionally their prosperous fellows gifted with the versatility to handle data and their analysis to create "intellectual doubt" or to support a positive conclusion.
Competing interests: No competing interests
The following issues may be pertinent:-
* The name/s of the manufacturers of the supplements are not disclosed
* Not all manufacturers produce the best money can make; cutting corners to boost product sales is not a novel strategy
* Do we know how much of the commercially (synthetically produced) available 'popular' calcium supplements is actually absorbed ? +/- 13 % !
* There are supplements for pregnant mothers that contain calcium that would hardly meet the RDA for a pregnant cat
Is it any surprise that the article in question finds the evidence in support of calcium for fractures wanting?
Competing interests: No competing interests
Re: Calcium supplements do not prevent fractures - response to dr Rhein
Dr Helga Rhein suggests we should put more focus on vitamin D supplementation rather than on calcium. However, this strategy might not lead to an improved health for our patients. With 4000 new vitamin D research publications each year, there is good possibility to find single studies that support your opinions. Even though there exists strong beliefs in the area of vitamin D effects, the problem is that vitamin D supplementation in meta-analyses of randomized clinical trials, our most rigorous method to evaluate treatment efficacy, has not at present been unequivocally proven to reduce disease burden (1, 2). Even in the case of bone health and in contrary to common assumptions, vitamin D supplementation alone does not provide a clear positive effect on bone mineral density (3) and does not reduce rates of falls (4, 5) or fractures (2, 6). Furthermore, compared with more moderate intakes, there is no proof that a mineral rich diet in childhood will render a better bone health at old age (7). However, we need to define true vitamin D deficiency in a better way – a message emphasized in my editorial (8). Naturally, there exists a lower limit for sufficient vitamin D status but it might be lower than many presently think (9).
Regarding the large proportion of vitamin D deficient in Scotland, it is dependent on both the definition of deficiency, which is a moving target, and the analytical method to determine vitamin D status. In the study by Purdon et al (dr Rhein’s reference No 2), plasma 25-hydroxyvitamin D was measured using the DiaSorin chemiluminecent immunoassay (Liasion). We know that this assay underestimates the actual serum/plasma concentration of 25-hydroxyvitamin D, and therefore overestimates the proportion with vitamin D insufficiency, compared to the gold standard method (LC-MS/MS) (10-12). This inaccuracy may have large impacts on the clinical interpretation. While a third of the Scottish population had sub-optimal serum 25-hydroxyvitamin D concentrations (<25 nmol/L by DiaSorin Liasion), the large majority (99%) living close to the Arctic Circle in Sweden have adequate serum 25-hydroxyvitamin D concentrations (by LC-MS/MS) even during the second half of the dark winter (13). A modest part of this large discrepancy in vitamin D status between the populations can be explained by different food fortification and dietary intake patterns (14) and genetics (15) but a more likely explanation is different methods used in the analysis of serum 25-hydroxyvitamin D. The Liasion assay provided by DiaSorin has recently been modified such that the difference compared to the gold standard is smaller but still exists (16).
References
1. Theodoratou E, Tzoulaki I, Zgaga L, Ioannidis JP. Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials. BMJ. 2014;348:g2035.
2. Bolland MJ, Grey A, Gamble GD, Reid IR. The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis. The lancet Diabetes & endocrinology. 2014;2(4):307-20.
3. Reid IR, Bolland MJ, Grey A. Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis. Lancet. 2014;383(9912):146-55.
4. Bolland MJ, Grey A, Gamble GD, Reid IR. Vitamin D supplementation and falls: a trial sequential meta-analysis. The lancet Diabetes & endocrinology. 2014;2(7):573-80.
5. Bolland MJ, Grey A, Reid IR. Differences in overlapping meta-analyses of vitamin D supplements and falls. J Clin Endocrinol Metab. 2014;99(11):4265-72.
6. Moyer VA, Force* USPST. Vitamin D and calcium supplementation to prevent fractures in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2013;158(9):691-6.
7. Slemenda CW, Peacock M, Hui S, Zhou L, Johnston CC. Reduced rates of skeletal remodeling are associated with increased bone mineral density during the development of peak skeletal mass. J Bone Miner Res. 1997;12(4):676-82.
8. Michaelsson K. Calcium supplements do not prevent fractures. BMJ. 2015;351:h4825.
9. Gallagher JC, Jindal PS, Smith LM. Vitamin D does not increase calcium absorption in young women: a randomized clinical trial. J Bone Miner Res. 2014;29(5):1081-7.
10. Binkley N, Krueger D, Cowgill CS, Plum L, Lake E, Hansen KE, et al. Assay variation confounds the diagnosis of hypovitaminosis D: a call for standardization. J Clin Endocrinol Metab. 2004;89(7):3152-7.
11. Enko D, Fridrich L, Rezanka E, Stolba R, Ernst J, Wendler I, et al. 25-hydroxy-Vitamin D status: limitations in comparison and clinical interpretation of serum-levels across different assay methods. Clin Lab. 2014;60(9):1541-50.
12. Snellman G, Melhus H, Gedeborg R, Byberg L, Berglund L, Wernroth L, et al. Determining vitamin D status: a comparison between commercially available assays. PLoS One. 2010;5(7):e11555.
13. Ramnemark A, Norberg M, Pettersson-Kymmer U, Eliasson M. Adequate vitamin D levels in a Swedish population living above latitude 63 degrees N: The 2009 Northern Sweden MONICA study. Int J Circumpolar Health. 2015;74:27963.
14. Burgaz A, Akesson A, Oster A, Michaelsson K, Wolk A. Associations of diet, supplement use, and ultraviolet B radiation exposure with vitamin D status in Swedish women during winter. Am J Clin Nutr. 2007;86(5):1399-404.
15. Snellman G, Melhus H, Gedeborg R, Olofsson S, Wolk A, Pedersen NL, et al. Seasonal genetic influence on serum 25-hydroxyvitamin D levels: a twin study. PLoS One. 2009;4(11):e7747.
16. Wyness SP, Straseski JA. Performance characteristics of six automated 25-hydroxyvitamin D assays: Mind your 3s and 2s. Clin Biochem. 2015.
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Competing interests: No competing interests