Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition study (EPIC-Heidelberg), Heart Journal 2012; 98:920-925
As a manufacturer of vitamins, mineral and supplements, Swiss NaturalTM wanted to send out a communication regarding the above study which has received quite a bit of media coverage over the past week.
Please be advised that Health Canada meticulously reviews all our vitamin, mineral and supplement products for safety and efficacy. Once a product is deemed safe and efficacious (through various proven clinical evidence published in peer-reviewed publications of scientific merit), Health Canada issues an NPN number. Products with an E-number have been deemed safe and are in queue to be assessed for efficacy to receive an NPN number. Health Canada has their own Monographs (guidelines for all vitamins and minerals) to which we comply with. The RDA (Recommended Daily Allowance) and UL (Tolerable Upper Intake) values are established by the Food and Nutrition Board of the Institute of Medicine in collaboration with Health Canada.
A study was recently published suggesting that calcium supplements increase the risk of heart attacks. This study was originally designed to investigate Cancer and Nutrition. It was not designed to evaluate cardiovascular incidence.
The study included 23,980 participants, aged 35-64 years. Eleven years after recruitment, follow-up was conducted with the participants now ranging from 46-75 years of age. The participants were deemed to be free of major cardiovascular events (eg. heart attack and stroke) at recruitment; however, many other pre-existing forms of cardiovascular disease (CVD) were excluded from the scope of the study. Participants completed a self-administered food frequency questionnaire (FFQ). FFQs often contain measurement errors as it becomes difficult to capture long-term variations or modifications throughout an 11 year period (i.e. increases in high sugar or fatty foods, or decreases in protein foods). Another limitation in the questionnaire was that it was restricted to 148 food items, not allowing assessment of many other potential risk factors.
The calcium supplement users were 3.6% of the total number of respondents (approximately 863 participants). The study defined calcium supplement use as either ”daily use for at least 1 week” or
“non-daily use of at least 5 doses on a regular basis in the past 4 weeks”. Respondents were not asked to report their daily intake amount of calcium. “Compared with non-users, users of calcium supplements were more likely to be women, physically more active and less likely to be overweight/obese. On the other hand, users of calcium supplements had an older age, an overall lower educational level and a longer duration of smoking.” Many of the attributes of the calcium supplement users, i.e. older, lower education and smokers, are all proven factors in peer-reviewed clinical studies to be associated with increased risk of CVD or heart attack.
The study has several limitations:
- Dietary data measurement errors
- Exclusion of pre-existing CVD events
- Unreported daily intake of calcium
- Low 3.6% reported calcium supplement users (however other participants may have been unreported users which would have brought down the MI incidence)
- Calcium supplement user risk profile
- These limitations put into question the authors’ hypothesis that “…calcium supplements, which might raise MI risk, should be taken with caution.”
Calcium is an important mineral to maintain bone health. Many studies support the use of calcium particularly in the elderly, who are at risk of fractures and falls due to weak bones / osteoporosis. Consumers should ensure they obtain enough calcium from dietary sources and supplements to maintain bone health and discuss their particular needs with a health care practitioner.
We value your opinions and appreciate your concerns on this issue. Thank you for supporting Swiss Natural™ and continuing to place your trust in our quality products.
CEO & President
Swiss Herbal Remedies Ltd.