A new study finds supplementing with calcium may slightly increase risk of heart attacks. Researchers suggest a review of current calcium recommendations.
A study published in the British Medical Journal found that calcium supplements commonly prescribed to benefit skeletal health, may increase the risk of a heart attack and cardiovascular events such as stroke, in healthy older women by 20% to 30%.
Calcium and Osteoporosis
While the increased risk is small, and some researchers say the findings are unnecessarily alarmist, given the widespread use of calcium supplements to help prevent osteoporosis, even a small risk within a large population could become a health burden, warns the study’s lead researcher Dr. Ian Reid.
Calcium supplementation has proven to provide only minimal benefit to increase bone density and to prevent fractures in women. As a result of its limited use for osteoporosis patients and the new heart risk findings, Reid suggests the current supplement recommendations be re-assessed.
In an editorial published with the study, cardiologist John Cleland of the U.K.’s Hull York Medical School called the analysis “concerning but not convincing.” Like Reid however, Cleland remains cautious. “Given the uncertain benefits of calcium supplements, any level of (heart) risk is unwarranted.”
Council for Responsible Nutrition Questions Implications
Dr. Andrew Shao, senior VP, scientific & regulatory affairs with the Council for Responsible Nutrition (CRN) says in a press release for CRN that the warnings have been overstated and dilute the importance of calcium. Calcium’s role in building and maintaining bone is vital says Shao, and to prevent osteoporosis. “The results from this meta-analysis does not undermine the value calcium supplements offer to those concerned with maintaining or increasing bone density, as years of research shows these products do,” he says.
The problem explains Shao, is the meta-analysis only included 15 randomized trials on calcium, rather than the available 300. Moreover, seven of the 15 trials had no, or incomplete data on cardiovascular outcomes and the study excluded studies that combined calcium with vitamin D. “This analysis should not dissuade consumers, particularly young women, from taking calcium supplements. They should talk with their doctors about their current and long-term needs and determine how much calcium they are getting from their diets, and supplement accordingly, likely in combination with vitamin D,” says Shao.
Vitamin D and Heart Health
Vitamin D, actually a secosteroid hormone, is gaining increasing attention among researchers. Once largely associated with bone health, studies indicate vitamin D may play an essential role in a wide array of key body functions including immunity, cancer prevention, and heart health.
“Vitamin D deficiency is an unrecognized, emerging cardiovascular risk factor, which should be screened for and treated,” says researcher James H. O’Keefe, MD, director of preventive cardiology at the Mid America Heart Institute in Kansas City, Mo., in a news release. “Vitamin D is easy to assess, and supplementation is simple, safe and inexpensive.”
The December 2008 issue of The Harvard Heart Letter reported on the link between vitamin D and heart health, writing that calcium deposits that stiffen the arteries are more likely to develop in people with low levels of vitamin D and cause coronary artery disease. Like low magnesium, a D deficiency contributes to high blood pressure, a risk factor for heart attack and stroke.
Jennifer Warner in her WebMD article “Too Little Vitamin D Puts Heart at Risk,” writes that researchers are finding a growing body of evidence to suggest a vitamin D deficiency increases the risk of heart disease and is linked to other, well-known heart disease risk factors such as high blood pressure, obesity, and diabetes.
Magnesium and Heart Health
Another unsung hero involved in heart health is magnesium. Dr. Carolyn Dean, Medical Director of the Nutritional Magnesium Association and author of several books including The Magnesium Miracle, has long warned doctors and the public against over promoting calcium and under promoting magnesium.
Magnesium is a mineral that plays a critical role in heart health and balances the effects of calcium. Most calcium-magnesium formulations however, have a 2:1 (or higher) ratio. Dr. Dean recommends the inverse, 2:1 magnesium.
Andrea Rosanoff, Ph.D.Director with the Center for Magnesium Education & Research writes in her book The Magnesium Factor, “The most important marker for impending heart disease is a low magnesium to calcium ratio in the cells.” Rosanoff’s co-author, Dr. Mildred Seelig writes, ”While several essential nutrients are imperative for heart and blood vessel health, the vast research on low magnesium and its impact on heart health has gone unheeded, so much so that much of the heart disease seen today is a direct result of low magnesium consumption.”
In recent decades calcium supplementation has been heavily promoted to prevent osteoporosis, build bone density and prevent fractures, yet results have been disappointing. Calcium, a new finding suggests, may actually increase the risk of heart attack. Yet magnesium and vitamin D once largely in the shadow of calcium, are gaining attention for their role in the prevention of a wide array of diseases and to improve overall health functioning, including heart health.
Boyles, Salynn, “Calcium May Increase Heart Attack Risk, WebMD Health News. July 29, 2010.
Bolland MJ, Avenell A, Baron JA, Grey A, Maclennan GS, Gamble GD, Reid IR., “Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis.” British Medical Journal, 2010 Jul 29.
Rosanoff, Arlene, Ph.D. and Seelig, Mildred. The Magnesium Factor, Penguin, 2003.
“Vitamin D deficiency bad for the heart, bones, and rest of the body,” Harvard Heart Letter, December 2009, Harvard Health Publications, Harvard Medical School.
Warner, Jennifer, “Too Little Vitamin D Puts Heart at Risk.” WebMD Health News. Dec. 1, 2008.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
Copyright Laura Owens. Contact the author to obtain permission for republication.
While 30% of women suffer from PMS each month, up to 8% suffer from a more extreme form, premenstrual dysphoric disorder (PMDD). Although the exact cause is still largely unknown, research suggests an increase in estrogen with changes in subsequent vitamin D and calcium synthesis may be involved.
PMDD Emotional Symptoms More Severe Than PMS
While PMS and PMDD both manifest with physical and emotional symptoms, PMDD causes more extreme mood shifts in women that can interfere with their work and relationships. PMDD symptoms occur during the luteal phase (latter part) of the menstrual cycle and are virtually non-existent during the follicular phase.
PMDD disappears at menopause, remits during pregnancy, and improves with ovarian hormone suppression therapy. In both PMS and PMDD, women experience symptoms in the last week of the menstrual cycle which generally improve a few days after menstruation begins.
PMDD and PMS both share symptoms of bloating, breast tenderness, fatigue, and changes in sleep and eating habits, but women with PMDD often experience a combination of the following emotional and behavioral symptoms:
- Feelings of being “keyed up” or “on edge”
- Mood swings
- Persistent irritability
- Marked anger
While the exact cause is unclear, research has shown a link between calcium deficiency and mood abnormalities which suggest PMDD may be linked to extreme fluctuations in calcium-regulating hormones in some women during their menstrual cycle.
Calcium Improves PMS & PMDD Symptoms
In a 2007 study on calcium and PMDD, lead author Susan Thys-Jacobs writes, “women with PMS were shown to have exaggerated fluctuations of the calcium regulating hormone across the menstrual cycle with evidence of vitamin D deficiency and secondary hyperparathyroidism.”
Thys-Jacobs’ research team investigated calcium’s role in PMS and PMDD based on earlier evidence linking mood disturbances and calcium metabolism. “On the basis of previous studies linking abnormalities in mood,” writes the author, “this investigation has now found that the pattern of cyclical fluctuations in the calcium-regulating hormones, specifically ionized calcium, urine calcium, and 1,25 (OH)2D (vitamin D) differs between women with PMDD and those without.”
Although there’s still no consensus among scientists the degree to which calcium-regulating hormones vary in women with PMDD, the 2007 study indicated that serum calcium declines at three points during a woman’s cycle: at menses, at mid-cycle, and during the late luteal half of her menses.Vitamin D Synthesis Involved in PMDD Symptoms
The research team found that although women with and without PMDD symptoms were low in vitamin D, women with PMDD metabolized vitamin D differently during their menstrual cycle than women without PMDD. Asymptomatic women had more access to stored calcium in their body during their menstrual cycle than women with symptoms. Researchers believe vitamin D plays a role in regulating the level of calcium released during the menstrual cycle.
Estrogen is likely involved as well. Estradiol, a component of estrogen, peaks during the ovulatory and luteal phase of menstruation to regulate vitamin D metabolism and to help prevent bone loss by keeping bone from being reabsorbed. When estrogen inhibits calcium from being released from bone, it lowers serum calcium which leads to a rise in the parathyroid hormone, triggering an increase in 1,25(OH) 2,D synthesis. Elevated 1,25(OH) 2,D may contribute to vitamin D and calcium deficiency, and subsequently cause PMDD symptoms.
While the exact cause of Premenstrual Dysphoric Disorder is still unknown, a growing body of evidence suggests there may be a link between elevated estrogen levels and how vitamin D and calcium are metabolized in some women during their menstrual cycle.Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
- Bertone-Johnson ER, Hankinson SE, Bendich A, Johnson SR, Willett WC, Manson JE. “Calcium and vitamin D intake and risk of incident premenstrual syndrome.” Archives of Internal Medicine, June 13, 2005.
- Khajehei M, Abdali K, Parsanezhad ME, Tabatabaee HR. “Effect of treatment with dydrogesterone or calcium plus vitamin D on the severity of premenstrual syndrome.” International Journal of Gynecology and Obstetrics, May 2009.
- Thys-Jacobs S, McMahon D, Bilezikian JP. “Cyclical changes in calcium metabolism across the menstrual cycle in women with premenstrual dysphoric disorder.” Journal of Clinical Endocrinology and Metabolism, May 2007.