The authors pooled 15 placebo controlled trials of calcium supplements of 500 mg a day or more, taken without vitamin D, by adults with a mean age above 40. People assigned to calcium had more heart attacks than people assigned to placebo. Rates of stroke and death were slightly higher but did not reach statistical significance, and the authors call for the role of calcium supplements in osteoporosis care to be reassessed.
Calcium supplements are widely taken by people over 50 for bone health. Evidence on the heart pointed two ways: observational studies suggested high calcium intake might protect blood vessels, but in kidney failure calcium supplements speed up hardening of the arteries and raise death rates. A five-year trial in healthy older women then reported possible increases in heart attacks. The authors pooled the randomized evidence to test whether calcium supplements raise cardiovascular risk.
This was a meta-analysis at two levels: individual participant data where researchers shared it, and summary trial data where they did not. Trials qualified if they were randomized, double blind and placebo controlled, gave at least 500 mg of elemental calcium a day, ran over a year, and randomized at least 100 people whose mean age was over 40. Trials of calcium plus vitamin D against plain placebo were excluded, because vitamin D has itself been linked to lower mortality. Fifteen qualified: five supplied patient-level data on 8151 participants, median follow-up 3.6 years (interquartile range 2.7 to 4.3), and eleven supplied trial-level data on 11,921 participants over a mean of 4.0 years. Pre-specified outcomes were time to first heart attack, first stroke, the combination of heart attack, stroke or sudden death, and death from any cause.
In the patient-level analysis, 143 people on calcium had a heart attack against 111 on placebo.
The trial-level analysis agreed: 166 heart attacks on calcium against 130 on placebo, pooled relative risk 1.27 (1.01 to 1.59, P=0.038). Stroke was 1.12 (0.92 to 1.36) and death 1.07 (0.95 to 1.19), neither statistically significant. The excess appeared in people whose dietary calcium was already above the median of 805 mg a day, hazard ratio 1.85 (1.28 to 2.67), and not in those below it, 0.98 (0.69 to 1.38), P for interaction 0.01. The authors calculate that treating 1000 people for five years would cause about 14 extra heart attacks, 10 strokes and 13 deaths, and prevent 26 fractures.
Trials of calcium with vitamin D were excluded by design, so the result does not describe that combination, which is how many people take calcium. Patient-level data covered only 63% of participants, and no cardiovascular data at all were available for four trials. Cardiovascular events were not the primary outcome of any included trial, and in some came from unadjudicated self-reports. Ian Reid received research support from and consulted for Fonterra, a dairy company. Four authors had study drugs for calcium trials supplied by Wyeth, Mission Pharmacal, Shire Pharmaceuticals and Nycomed. Funding came from the Health Research Council of New Zealand and the University of Auckland School of Medicine Foundation. Participants were mostly older women, mean age about 75.
This is a cautionary result. Pooled randomized trials found about a 30% higher rate of heart attack in people given calcium supplements without vitamin D, with increases in stroke and death pointing the same way but not statistically significant. The population was mostly elderly women taking supplements for bone health, so it does not automatically extend to younger or healthier people. It says nothing about calcium from food: the authors note that observational studies of dietary calcium show no such harm, and that dairy calcium raises blood calcium far less than supplements. The authors conclude that the role of calcium supplements in osteoporosis needs reassessment, given the modest fracture benefit alongside this risk.
That depends on the specific medication and formula. A few, like blood thinners with CurQLife or blood pressure medication with MaxiNOs, are worth a direct conversation with your doctor first. Check each formula's own FAQ section for specifics, or ask your health coach.
No, and we'd rather be upfront about it. Bacopa, the plant in BacoZest, has published human studies, though they used other bacopa extracts. OptiNOs and MaxiNOs each have human studies sponsored by their maker, Laila Nutraceuticals, which haven't been published in a journal. CurQLife's research is still early, from lab and animal studies, and we label it that way.
It depends on what you're building your routine around. BacoZest is built around bacopa, which is studied for memory.* OptiNOs supports strength and muscular endurance alongside resistance training.* MaxiNOs was studied for healthy blood vessel function.* CurQLife's research is still at the lab stage. Your health coach can help you pick a starting point.
All four are built around plant extracts. OptiNOs was reported as well tolerated in its human study, and published bacopa studies reported no serious side effects. CurQLife's safety data so far comes from lab and animal testing. Check with your doctor first if you're pregnant, nursing, on medication, or managing a health condition.
Because the patented ingredients behind our four formulas went through dedicated research, and research costs real money. A generic curcumin or bacopa supplement hasn't been tested in the form you get from us. You're paying for an ingredient with research behind it, not just a label.
Generic ingredients often haven't been studied in the specific form you're buying. Our four core formulas use patented ingredients, and we show you the research behind each one, including where it's still early.
It depends on the formula. In its study, MaxiNOs blood vessel response was higher than placebo 2 to 3 hours after the first dose.* OptiNOs and bacopa were studied over 6 and 12 weeks of daily use, so give them time. CurQLife is meant to be taken daily.
Yes. BacoZest, OptiNOs, MaxiNOs, and CurQLife are built for different goals, and none of them contain stimulants. They haven't been studied together, so ask your health coach how to fit them into your routine.
