Women: Calcium, Vit D Supplements
Good for Bones
confusion over vitamin D and calcium seems likely to grow, following claims
from the Women's Health Initiative (WHI) trial about their effect on bone
health that oppose other studies. The combination of vitamin D and calcium has
long been recommended to reduce the risk of bone fracture for older people,
particularly those at risk of or suffering from osteoporosis, which is
estimated to affect about 75 million people in Europe, the USA and Japan.
Use of these supplements is widely accepted by the general public, with calcium
reported to be the biggest seller in the US supplements industry, with annual
sales of about $993 (?836) million in 2004, according to the Nutrition Business
Journal. The new study poses a challenge to this acceptance by concluding that
calcium and vitamin D supplements did not reduce the risk of fractures in
Published in the New England Journal of Medicine (Vol. 354, pp. 669-683), the
study followed 36,282 post-menopausal women with an average age of 62 at the
start of the trial. Volunteers were randomly assigned to receive 1000 mg of elemental
calcium in the carbonate form and 400 IU of vitamin D3 per day, or a placebo.
After an average of seven years of follow-up the scientists reported:
"Among healthy postmenopausal women, calcium with vitamin D
supplementation resulted in a small but significant improvement in hip bone
density, and did not significantly reduce hip fracture."
Such a sweeping generalization is somewhat misleading however. If one looks
just at the 59 percent of the participants who actually adhered to the
supplementation program (assuming 80 percent or more compliance with taking the
supplements), the data do, in fact, highlight the benefits of dual vitamin
The number of fractures in this compliant group was 29 percent lower than
placebo. This indicates that supplementation with calcium and vitamin D did
significantly reduce the risk of hip fracture, as has been reported by other
studies, but only if taken regularly. The bone mineral density of the entire
intervention group increased by 0.86 percent after six years, and for those
followed-up for nine years, BMD increased by 1.06 percent.
The strengths of this study lie in the large-scale, randomized, double-blind,
placebo-based design. However the authors recognize that adherence to an
intervention using a free-living population is difficult. Indeed, even though
the placebo group was not given the supplements by the researchers, they were
free to use supplements on their own. Sixty-four percent of the placebo group
had a daily calcium intake of at least 800 mg from diet and supplements, and 42
percent were consuming at least 400 IU of vitamin D.
This suggests that the intervention and control groups were very similar. With
both groups consuming calcium and vitamin D, this could explain why the incidence
of overall fractures was less than envisaged - the actual hip fracture rate was
more than half that projected by the researchers. "The
lower-than-projected hip-fracture rate reduced the power of the study to
approximately 48 percent," wrote the research team, led by Rebecca Jackson
from Ohio State University.
In an accompanying editorial, Joel Finkelstein from the Massachusetts General
Hospital rightly points out: "There were several aspects of the study
design and characteristics of the study population that may have reduced the
chances of detecting a benefit of calcium and vitamin D." It should be
pointed out that many of the women were involved in the other arms of the WHI
trial, with 69 percent of the women enrolled on the Dietary Modification trial,
54 percent enrolled on the Hormone Therapy trial, and 14 percent enrolled on
"The use of hormone-replacement therapy (HRT) among post-menopausal women
has declined dramatically [HRT is known to be potent against bone resorption
and weakening and can reduce bone fracture]. Thus, the widespread use of HRT in
the current study limits the ability to generalize the results," he said.
Another limitation, the dose of vitamin D might have been too small to initiate
a response for all participants. Other studies have reported no effect with 400
IU, but benefits have been reported for trials using doses of 600 IU or more.
However, it seems plausible that the dose was not as significant as adherence
to the program. The data clearly show that women who regularly took the
vitamins had a 29 percent reduction in hip fractures.
Finkelstein finishes a well-balanced editorial by concluding: "It seems
reasonable that women consume the recommended daily levels of calcium and
vitamin D through diet, supplements, or both. But one message is clear: calcium
with vitamin D supplementation by itself is not enough to ensure optimal bone
This statement was echoed by Roger Francis, Professor of Geriatric Medicine at
the University of Newcastle, who told NutraIngredients.com: "This study
shows that vitamin D and calcium supplementation would not work as a public
health measure, because vitamin D - calcium trials have notoriously poor
Professor Francis pointed out however that an earlier French study (Scand J
Rheumatol Suppl. 1996 Vol. 103, pp. 75-78) reported that calcium and vitamin D
supplements given to elderly women significantly reduced the risk of hip
fracture. This sample population was much older than the WHI population.
The current EU recommended daily intake of calcium is 800 mg, with an upper
safe limit of 2500 mg. Vitamin D has a RDI of 400 IU, although campaigners are
calling for an increase to 1000 IU, half the upper safe limit recommended by
the EU and US. In the US, the DRI (dietary reference intake) for calcium is
1000mg for adults aged 19 to 50, and 1200mg from 51 to 70. For vitamin D it is
five micrograms per day, rising to 10 after the age of 50. According to the
International Osteoporosis Foundation, the total direct cost of osteoporotic
fractures is 31.7 billion euros ($37.6) in Europe, and $17.5 (?14.7) billion in
the US (2002 figure).
An important point to keep in mind is that data clearly show that women who
regularly took the vitamins had a 29 percent reduction in hip fractures.
Click here to see Calcium at
E-mail Us: info@LifesourceVitamins.com
Call Us: 800.567.8122
We Are Built on Compassion - Driven by Faith & Powered by
Questions? It can be overwhelming we know. Call us, we will walk you through what
supplements will help you and which ones you really don’t need. It’s
what we do!
*Disclaimer: None of the above statements
have been evaluated by the FDA. These products are not intended to diagnose,
treat, cure or prevent any disease. As always, consult your physician before
taking any and all supplements. LifeSource Vitamins. Individual results may
Disclaimer: All the
information contained throughout this website is based upon the opinion of the
founder of LifeSource Vitamins, Bruce Brightman, and the entire team at
LifeSource Vitamins whose relentless research and studies have been ongoing on
since 1992. Other articles and
information are based on the opinions of the authors, who retains the copyright
as marked on the article. The
information on this site is not intended to replace your health care
professional, but to enhance your relationship with them. Doing your own studying and research and
taking your health care into your own hands is always best, especially in
partnership with your health care professional.
If you are pregnant, nursing, taking medications, or have any medical
conditions, always consult your health care professional before taking
supplements based on the information on this site.