User login
Some doctors may be scratching their heads over a new analysis reporting that combined calcium and vitamin D (CaD) supplements appear to be associated with a slight 6% increase in cardiovascular (CVD) mortality, a slight 7% decrease in cancer risk, and no effect on osteoporotic fracture in postmenopausal women.
The study, in Annals of Internal Medicine, found no effect of supplementation on all-cause mortality.
The findings emerged from an analysis of more than 20 years’ follow-up data on a randomized trial in postmenopausal women conducted as part of the Women’s Health Initiative (WHI).
Cynthia A. Thomson, PhD, RD, first author and cancer prevention scientist at the Arizona Cancer Center and a professor of health promotion sciences at the University of Arizona in Tucson said the findings recommend individualized assessment of the need for supplements for older women as they consider them in hopes of preventing fractures.
“Evaluate your patients individually and understand that there are some who may benefit from supplementation, for example, in terms of reducing colorectal cancer mortality,” Dr. Thomson said in an interview. The approach should be nuanced. “If you check the adequacy of vitamin D and calcium in their diets, supplementation may not be needed.” She added that supplementation is best considered in the context of a woman’s overall health profile, including risk factors for fracture, heart disease, and cancer, especially colorectal cancer (CRC).
Study Details
The investigators conducted postintervention follow-up of the WHI’s 7-year multicenter randomized intervention trial of CaD vs placebo.
Since existing evidence of long-term health outcomes was limited, the trial, begun in 1999 and closed in 2005, enrolled 36,282 postmenopausal women (mean age 62) with no history of breast or colorectal cancer. They were randomly assigned 1:1 to supplementation with 1000 mg of calcium carbonate (400 mg elemental calcium) plus 400 IU of vitamin D3 daily or placebo, taken twice daily in half doses.
Study outcomes were incidence of CRC, total and invasive breast cancer; disease-specific and all-cause mortality; total CVD; and hip fracture measured through December 2020, with analyses stratified by personal supplement usage.
Cancer. CaD was associated with reduced incident total cancer, CRC, and invasive breast cancer — notably among participants not taking CaD before randomization. Cancer incidence estimates varied widely, the authors noted, when stratified by supplement use before randomization. Noting that CaD seemed to have more cancer-related impact in those without prior supplementation, the authors suggested supplementation may affect cancer biology primarily by augmenting nutrient insufficiency.
An estimated 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years: 1817 vs 1943 deaths (hazard ratio, 0.93; 95% CI, 0.87-0.99).
CVD. An estimated 6% increase in CVD mortality was seen in the CaD group: 2621 vs 2420 deaths (HR, 1.06; 95% CI, 1.01-1.12). Pretrial supplement users were found to be at higher CVD risk.
Hip fracture. No effect on hip fracture risk was measured, but the authors cautioned that hip fracture and CVD outcomes were available only for a subset of participants, and the effects of calcium alone vs vitamin D alone vs the combination could not be disentangled.
In a small subgroup analysis, some CaD users were seen to respond in terms of bone mineral density but since only 4 of the study’s 40 sites collected such information, the study was underpowered to examine the effect. ”Many other studies, however, show a response to supplementation in women who already have bone mineral deficits,” Dr. Thomson said.
The Calcification Question
One of the possible mechanisms of harm is that high-dose calcium supplements can increase the rate of blood coagulation and promote vascular calcification, said Emma Laing, PhD, RD, director of dietetics at the University of Georgia in Athens and a spokesperson for the Chicago-based Academy of Nutrition and Dietetics.
“Other factors that should be considered when determining a patient’s CVD risk are race, genetic predisposition, medical and social history, response to stress, and lifestyle behaviors, as well as the length of time supplements have been consumed,” added Dr. Laing, who was not involved in the WHI analysis.
“We asked ourselves if CaD supplements might contribute to calcification of the coronary arteries, since some believe this to be the case, although the literature is mixed,” said Dr. Thomson.
“So we did a shorter ancillary study in a small sample of several hundred [women] to see if there was any increase in calcification” and no difference was seen on imaging across the two arms. “However, women who were already on supplements before entering the study seemed to be at higher CVD risk,” she said.
Added study coauthor JoAnn E. Manson, MD, DrPH, chief of the division of preventive medicine at Brigham and Women’s Hospital and professor of women’s health at Harvard Medical School, both in Boston: “With no increase or decrease in coronary artery calcium at the end of the trial, we don’t believe starting or continuing calcium/vitamin D supplements should require screening for coronary artery disease.”
Some randomized trials and systematic reviews, however, have observed an increased risk of CVD in healthy patients on calcium supplements, with one Korean meta-analysis reporting a 15% increase in CVD risk in healthy postmenopausal women taking calcium supplements. Another meta-analysis found a link between calcium supplements and a greater risk of various cardiovascular outcomes, especially myocardial infarction.
Vitamin D Supplementation
As for vitamin D only supplementation, an updated meta-analysis including more than 83,000 individuals showed that it confers no cardiovascular protection and is therefore not indicated for this purpose.
Practice Considerations
Offering an outsider’s perspective, Sarah G. Candler, MD, MPH, an internist in Houston specializing in primary care for older high-risk adults, said: “Unfortunately, this latest study continues the trend of creating more questions than answers. If the adverse outcome of CVD death is a result of supplementation, it is unclear if this is due to the vitamin D, the calcium, or both. And it is unclear if this is dose dependent, time dependent, or due to concurrent risk factors unique to certain populations.
“It is recommended that patients at risk of osteoporosis based on age, sex, medications, and lifestyle be screened for osteoporosis and treated accordingly, including supplementation with CaD,” Dr. Candler said. “It remains unclear whether supplementation with CaD in the absence of osteoporosis and osteopenia is net beneficial or harmful, and at this time I would not recommend it to my patients.”
Added Dr. Manson: “The very small increase seen in cardiovascular mortality wouldn’t be a reason to discontinue supplementation among women who have been advised by their healthcare providers to take these supplements for bone health or other purposes.
“Among those at usual risk of fracture, we recommend trying to obtain adequate calcium and vitamin D from food sources first and to use supplements only for the purpose of filling gaps in intake,” Dr. Manson continued. Overall, the findings support the national recommended dietary allowances for daily calcium intake of 1200 mg and daily vitamin D intake of 600-800 IU among postmenopausal women for maintenance of bone health, she said.
While a 2022 study found that vitamin D supplementation alone did not prevent fractures in healthy adults, other research has shown that a calcium/vitamin D combination is more likely to protect the skeleton.
“Patients at risk for fractures will probably benefit from calcium and/or vitamin D supplementation if they do not meet dietary intake requirements, have malabsorption syndromes, are taking medications that affect nutrient absorption, or if they are older and not regularly exposed to sunlight,” said Dr. Laing. “A combination of biochemical, imaging, functional, and dietary intake data can help determine if a supplement is warranted.”
She stressed that additional research is needed in more diverse populations before changing practice guidelines. “However, doctors should continue to weigh the risks and benefits of prescribing supplements for each patient.”
The WHI program is funded by the National Heart, Lung, and Blood Institute. Dr. Thomson disclosed no competing interests. Dr. Manson reported a relationship with Mars Edge. Multiple authors reported grant support from government funding agencies. The outside commentators had no relevant competing interests to disclose.
Some doctors may be scratching their heads over a new analysis reporting that combined calcium and vitamin D (CaD) supplements appear to be associated with a slight 6% increase in cardiovascular (CVD) mortality, a slight 7% decrease in cancer risk, and no effect on osteoporotic fracture in postmenopausal women.
The study, in Annals of Internal Medicine, found no effect of supplementation on all-cause mortality.
The findings emerged from an analysis of more than 20 years’ follow-up data on a randomized trial in postmenopausal women conducted as part of the Women’s Health Initiative (WHI).
Cynthia A. Thomson, PhD, RD, first author and cancer prevention scientist at the Arizona Cancer Center and a professor of health promotion sciences at the University of Arizona in Tucson said the findings recommend individualized assessment of the need for supplements for older women as they consider them in hopes of preventing fractures.
“Evaluate your patients individually and understand that there are some who may benefit from supplementation, for example, in terms of reducing colorectal cancer mortality,” Dr. Thomson said in an interview. The approach should be nuanced. “If you check the adequacy of vitamin D and calcium in their diets, supplementation may not be needed.” She added that supplementation is best considered in the context of a woman’s overall health profile, including risk factors for fracture, heart disease, and cancer, especially colorectal cancer (CRC).
Study Details
The investigators conducted postintervention follow-up of the WHI’s 7-year multicenter randomized intervention trial of CaD vs placebo.
Since existing evidence of long-term health outcomes was limited, the trial, begun in 1999 and closed in 2005, enrolled 36,282 postmenopausal women (mean age 62) with no history of breast or colorectal cancer. They were randomly assigned 1:1 to supplementation with 1000 mg of calcium carbonate (400 mg elemental calcium) plus 400 IU of vitamin D3 daily or placebo, taken twice daily in half doses.
Study outcomes were incidence of CRC, total and invasive breast cancer; disease-specific and all-cause mortality; total CVD; and hip fracture measured through December 2020, with analyses stratified by personal supplement usage.
Cancer. CaD was associated with reduced incident total cancer, CRC, and invasive breast cancer — notably among participants not taking CaD before randomization. Cancer incidence estimates varied widely, the authors noted, when stratified by supplement use before randomization. Noting that CaD seemed to have more cancer-related impact in those without prior supplementation, the authors suggested supplementation may affect cancer biology primarily by augmenting nutrient insufficiency.
An estimated 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years: 1817 vs 1943 deaths (hazard ratio, 0.93; 95% CI, 0.87-0.99).
CVD. An estimated 6% increase in CVD mortality was seen in the CaD group: 2621 vs 2420 deaths (HR, 1.06; 95% CI, 1.01-1.12). Pretrial supplement users were found to be at higher CVD risk.
Hip fracture. No effect on hip fracture risk was measured, but the authors cautioned that hip fracture and CVD outcomes were available only for a subset of participants, and the effects of calcium alone vs vitamin D alone vs the combination could not be disentangled.
In a small subgroup analysis, some CaD users were seen to respond in terms of bone mineral density but since only 4 of the study’s 40 sites collected such information, the study was underpowered to examine the effect. ”Many other studies, however, show a response to supplementation in women who already have bone mineral deficits,” Dr. Thomson said.
The Calcification Question
One of the possible mechanisms of harm is that high-dose calcium supplements can increase the rate of blood coagulation and promote vascular calcification, said Emma Laing, PhD, RD, director of dietetics at the University of Georgia in Athens and a spokesperson for the Chicago-based Academy of Nutrition and Dietetics.
“Other factors that should be considered when determining a patient’s CVD risk are race, genetic predisposition, medical and social history, response to stress, and lifestyle behaviors, as well as the length of time supplements have been consumed,” added Dr. Laing, who was not involved in the WHI analysis.
“We asked ourselves if CaD supplements might contribute to calcification of the coronary arteries, since some believe this to be the case, although the literature is mixed,” said Dr. Thomson.
“So we did a shorter ancillary study in a small sample of several hundred [women] to see if there was any increase in calcification” and no difference was seen on imaging across the two arms. “However, women who were already on supplements before entering the study seemed to be at higher CVD risk,” she said.
Added study coauthor JoAnn E. Manson, MD, DrPH, chief of the division of preventive medicine at Brigham and Women’s Hospital and professor of women’s health at Harvard Medical School, both in Boston: “With no increase or decrease in coronary artery calcium at the end of the trial, we don’t believe starting or continuing calcium/vitamin D supplements should require screening for coronary artery disease.”
Some randomized trials and systematic reviews, however, have observed an increased risk of CVD in healthy patients on calcium supplements, with one Korean meta-analysis reporting a 15% increase in CVD risk in healthy postmenopausal women taking calcium supplements. Another meta-analysis found a link between calcium supplements and a greater risk of various cardiovascular outcomes, especially myocardial infarction.
Vitamin D Supplementation
As for vitamin D only supplementation, an updated meta-analysis including more than 83,000 individuals showed that it confers no cardiovascular protection and is therefore not indicated for this purpose.
Practice Considerations
Offering an outsider’s perspective, Sarah G. Candler, MD, MPH, an internist in Houston specializing in primary care for older high-risk adults, said: “Unfortunately, this latest study continues the trend of creating more questions than answers. If the adverse outcome of CVD death is a result of supplementation, it is unclear if this is due to the vitamin D, the calcium, or both. And it is unclear if this is dose dependent, time dependent, or due to concurrent risk factors unique to certain populations.
“It is recommended that patients at risk of osteoporosis based on age, sex, medications, and lifestyle be screened for osteoporosis and treated accordingly, including supplementation with CaD,” Dr. Candler said. “It remains unclear whether supplementation with CaD in the absence of osteoporosis and osteopenia is net beneficial or harmful, and at this time I would not recommend it to my patients.”
Added Dr. Manson: “The very small increase seen in cardiovascular mortality wouldn’t be a reason to discontinue supplementation among women who have been advised by their healthcare providers to take these supplements for bone health or other purposes.
“Among those at usual risk of fracture, we recommend trying to obtain adequate calcium and vitamin D from food sources first and to use supplements only for the purpose of filling gaps in intake,” Dr. Manson continued. Overall, the findings support the national recommended dietary allowances for daily calcium intake of 1200 mg and daily vitamin D intake of 600-800 IU among postmenopausal women for maintenance of bone health, she said.
While a 2022 study found that vitamin D supplementation alone did not prevent fractures in healthy adults, other research has shown that a calcium/vitamin D combination is more likely to protect the skeleton.
“Patients at risk for fractures will probably benefit from calcium and/or vitamin D supplementation if they do not meet dietary intake requirements, have malabsorption syndromes, are taking medications that affect nutrient absorption, or if they are older and not regularly exposed to sunlight,” said Dr. Laing. “A combination of biochemical, imaging, functional, and dietary intake data can help determine if a supplement is warranted.”
She stressed that additional research is needed in more diverse populations before changing practice guidelines. “However, doctors should continue to weigh the risks and benefits of prescribing supplements for each patient.”
The WHI program is funded by the National Heart, Lung, and Blood Institute. Dr. Thomson disclosed no competing interests. Dr. Manson reported a relationship with Mars Edge. Multiple authors reported grant support from government funding agencies. The outside commentators had no relevant competing interests to disclose.
Some doctors may be scratching their heads over a new analysis reporting that combined calcium and vitamin D (CaD) supplements appear to be associated with a slight 6% increase in cardiovascular (CVD) mortality, a slight 7% decrease in cancer risk, and no effect on osteoporotic fracture in postmenopausal women.
The study, in Annals of Internal Medicine, found no effect of supplementation on all-cause mortality.
The findings emerged from an analysis of more than 20 years’ follow-up data on a randomized trial in postmenopausal women conducted as part of the Women’s Health Initiative (WHI).
Cynthia A. Thomson, PhD, RD, first author and cancer prevention scientist at the Arizona Cancer Center and a professor of health promotion sciences at the University of Arizona in Tucson said the findings recommend individualized assessment of the need for supplements for older women as they consider them in hopes of preventing fractures.
“Evaluate your patients individually and understand that there are some who may benefit from supplementation, for example, in terms of reducing colorectal cancer mortality,” Dr. Thomson said in an interview. The approach should be nuanced. “If you check the adequacy of vitamin D and calcium in their diets, supplementation may not be needed.” She added that supplementation is best considered in the context of a woman’s overall health profile, including risk factors for fracture, heart disease, and cancer, especially colorectal cancer (CRC).
Study Details
The investigators conducted postintervention follow-up of the WHI’s 7-year multicenter randomized intervention trial of CaD vs placebo.
Since existing evidence of long-term health outcomes was limited, the trial, begun in 1999 and closed in 2005, enrolled 36,282 postmenopausal women (mean age 62) with no history of breast or colorectal cancer. They were randomly assigned 1:1 to supplementation with 1000 mg of calcium carbonate (400 mg elemental calcium) plus 400 IU of vitamin D3 daily or placebo, taken twice daily in half doses.
Study outcomes were incidence of CRC, total and invasive breast cancer; disease-specific and all-cause mortality; total CVD; and hip fracture measured through December 2020, with analyses stratified by personal supplement usage.
Cancer. CaD was associated with reduced incident total cancer, CRC, and invasive breast cancer — notably among participants not taking CaD before randomization. Cancer incidence estimates varied widely, the authors noted, when stratified by supplement use before randomization. Noting that CaD seemed to have more cancer-related impact in those without prior supplementation, the authors suggested supplementation may affect cancer biology primarily by augmenting nutrient insufficiency.
An estimated 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years: 1817 vs 1943 deaths (hazard ratio, 0.93; 95% CI, 0.87-0.99).
CVD. An estimated 6% increase in CVD mortality was seen in the CaD group: 2621 vs 2420 deaths (HR, 1.06; 95% CI, 1.01-1.12). Pretrial supplement users were found to be at higher CVD risk.
Hip fracture. No effect on hip fracture risk was measured, but the authors cautioned that hip fracture and CVD outcomes were available only for a subset of participants, and the effects of calcium alone vs vitamin D alone vs the combination could not be disentangled.
In a small subgroup analysis, some CaD users were seen to respond in terms of bone mineral density but since only 4 of the study’s 40 sites collected such information, the study was underpowered to examine the effect. ”Many other studies, however, show a response to supplementation in women who already have bone mineral deficits,” Dr. Thomson said.
The Calcification Question
One of the possible mechanisms of harm is that high-dose calcium supplements can increase the rate of blood coagulation and promote vascular calcification, said Emma Laing, PhD, RD, director of dietetics at the University of Georgia in Athens and a spokesperson for the Chicago-based Academy of Nutrition and Dietetics.
“Other factors that should be considered when determining a patient’s CVD risk are race, genetic predisposition, medical and social history, response to stress, and lifestyle behaviors, as well as the length of time supplements have been consumed,” added Dr. Laing, who was not involved in the WHI analysis.
“We asked ourselves if CaD supplements might contribute to calcification of the coronary arteries, since some believe this to be the case, although the literature is mixed,” said Dr. Thomson.
“So we did a shorter ancillary study in a small sample of several hundred [women] to see if there was any increase in calcification” and no difference was seen on imaging across the two arms. “However, women who were already on supplements before entering the study seemed to be at higher CVD risk,” she said.
Added study coauthor JoAnn E. Manson, MD, DrPH, chief of the division of preventive medicine at Brigham and Women’s Hospital and professor of women’s health at Harvard Medical School, both in Boston: “With no increase or decrease in coronary artery calcium at the end of the trial, we don’t believe starting or continuing calcium/vitamin D supplements should require screening for coronary artery disease.”
Some randomized trials and systematic reviews, however, have observed an increased risk of CVD in healthy patients on calcium supplements, with one Korean meta-analysis reporting a 15% increase in CVD risk in healthy postmenopausal women taking calcium supplements. Another meta-analysis found a link between calcium supplements and a greater risk of various cardiovascular outcomes, especially myocardial infarction.
Vitamin D Supplementation
As for vitamin D only supplementation, an updated meta-analysis including more than 83,000 individuals showed that it confers no cardiovascular protection and is therefore not indicated for this purpose.
Practice Considerations
Offering an outsider’s perspective, Sarah G. Candler, MD, MPH, an internist in Houston specializing in primary care for older high-risk adults, said: “Unfortunately, this latest study continues the trend of creating more questions than answers. If the adverse outcome of CVD death is a result of supplementation, it is unclear if this is due to the vitamin D, the calcium, or both. And it is unclear if this is dose dependent, time dependent, or due to concurrent risk factors unique to certain populations.
“It is recommended that patients at risk of osteoporosis based on age, sex, medications, and lifestyle be screened for osteoporosis and treated accordingly, including supplementation with CaD,” Dr. Candler said. “It remains unclear whether supplementation with CaD in the absence of osteoporosis and osteopenia is net beneficial or harmful, and at this time I would not recommend it to my patients.”
Added Dr. Manson: “The very small increase seen in cardiovascular mortality wouldn’t be a reason to discontinue supplementation among women who have been advised by their healthcare providers to take these supplements for bone health or other purposes.
“Among those at usual risk of fracture, we recommend trying to obtain adequate calcium and vitamin D from food sources first and to use supplements only for the purpose of filling gaps in intake,” Dr. Manson continued. Overall, the findings support the national recommended dietary allowances for daily calcium intake of 1200 mg and daily vitamin D intake of 600-800 IU among postmenopausal women for maintenance of bone health, she said.
While a 2022 study found that vitamin D supplementation alone did not prevent fractures in healthy adults, other research has shown that a calcium/vitamin D combination is more likely to protect the skeleton.
“Patients at risk for fractures will probably benefit from calcium and/or vitamin D supplementation if they do not meet dietary intake requirements, have malabsorption syndromes, are taking medications that affect nutrient absorption, or if they are older and not regularly exposed to sunlight,” said Dr. Laing. “A combination of biochemical, imaging, functional, and dietary intake data can help determine if a supplement is warranted.”
She stressed that additional research is needed in more diverse populations before changing practice guidelines. “However, doctors should continue to weigh the risks and benefits of prescribing supplements for each patient.”
The WHI program is funded by the National Heart, Lung, and Blood Institute. Dr. Thomson disclosed no competing interests. Dr. Manson reported a relationship with Mars Edge. Multiple authors reported grant support from government funding agencies. The outside commentators had no relevant competing interests to disclose.
FROM ANNALS OF INTERNAL MEDICINE