Reprinted
from ABC Health and Well being. Posted 29 November 2019,
Vitamin D and
calcium are both essential for building healthy bones.
Vitamin D and
calcium supplements are often recommended to curb osteoporosis risk
New review
finds the vitamins have little value for people who are not vitamin deficient.
Calcium
supplements may even cause harm, and have no place in modern medicine, experts
say
Now, research
has revealed it might be time to ditch two of our most popular vitamins.
Calcium and
vitamin D supplements, often recommended to older Australians to prevent
osteoporosis, offer very little benefit to healthy adults.
In fact,
calcium supplements may be doing more harm than good.
While the
nutrients themselves are important, the researchers found calcium and vitamin D
supplements did little to reduce fracture risk or improve bone density in the
healthy older adult population.
The use of
vitamin D as a "general tonic" in individuals who were not vitamin D
deficient (or at risk of becoming deficient) was found to be largely fruitless.
"Just as
we would not expect antibiotics given to individuals without an active
infection to have beneficial effects, we should not expect supplements of
calcium and vitamin D to benefit people who do not have demonstrable
deficiency," the study authors wrote.
Calcium and
vitamin D supplements are often administered together for the prevention and
treatment of osteoporosis, which occurs when bones lose minerals, such as
calcium, more quickly than the body can replace them.
Previous
research into these supplements has produced conflicting results.
But this
latest review, which assessed the overall safety and effectiveness of
supplements, suggests the supplementation of calcium has little place in modern
medicine.
"When
you give extra calcium to otherwise healthy people living in the community, it
makes no material difference to the number of fractures that occur," lead
author Ian Reid, professor of medicine and endocrinology at the University of
Auckland.
"And the
main reason for giving extra calcium was a belief that that would make bones
stronger."
According to
the review article, calcium supplements can cause constipation, bloating and
kidney stones, and may increase the risk of heart attack.
"Calcium
supplements are frequently associated with gastrointestinal symptoms ... and
they have also been reported to double the risk of hospital admissions related
to abdominal symptoms," the authors wrote.
Vitamin D
supplements, on the other hand, rarely cause adverse health outcomes. But there
is evidence that very high levels of vitamin D can increase the risk of falls
and fractures.
Either way,
supplements were found to generally only have value in people with vitamin
deficiencies, and not across the healthy older population — so talk to your
doctor before starting or stopping any supplements.
Although the
evidence for supplements in osteoporosis treatment is not strong, Professor
Reid said there are some circumstances where they should still be used.
"Some of
the new drugs that we are currently using in osteoporosis have only been
assessed when calcium and vitamin D have been given at the same time, so I
think we need to proceed cautiously," he said.
The use of
calcium and vitamin D supplements in people at risk of vitamin D deficiency who
require antiresorptive therapies is appropriate.
"But the
most commonly used drugs ... it does not appear to matter. As long as your
vitamin D levels are satisfactory, not giving calcium doesn't make any
difference to the efficacy of those drugs," Professor Reid said.
Outside of
osteoporosis, there are some conditions, such as osteomalacia — a bone disease
in which bones soften and weaken — for which calcium and vitamin D supplements
are considered appropriate.
Vitamin D
supplementation is also advised for frail older people, and in some cases,
people who cover their bodies for religious or cultural reasons, who are at
risk of vitamin D deficiency.
Our main
source of vit D is from the sun, and the best parts of the day to get your sun
exposure and vitamin D dose in summer is the mid-morning or mid-afternoon.
For people
with fair skin, five to 15 minutes in the sunshine most days a week should do
it if your face and arms are exposed.
For people
with very fair skin, it's less than that, and for people with darker skin, it
can be a little longer.
