|
· Professional regulation
· Code of Ethics (2)
· The profession (4)
· Community pharmacy (2)
· Multiples
· Accuracy checking
· CPPE (3)
· Medicines use review
· Emergency supplies (2)
· Controlled Drugs
· NHS
· Nutrition
· Fellowship
· The Council
· Retention fees
· Section 60 Order
Letters to the Editor
|
Nutrition
Taking care of calcium in the diet
From Mr H. R. Patel, MRPharmS
The function of calcium is well covered in the Appleton and Lockwood’s
article, “Building
bones with nutraceuticals” (PJ, 15 July,
p78). They claim that milk is a good source of calcium. This is a common
belief and yet the key public health question is rarely asked: is calcium
from milk readily absorbed in the body? I have seen no evidence to suggest
that it is. If there is no evidence, then action needs to be taken to educate
the public, health care workers and advertisers.
Until clear evidence is available pharmacists should concentrate on giving
reliable advice based on evidence which shows that other foods are much
better at providing absorbable calcium. Also lactose-intolerant and vegan
individuals tend to avoid or eliminate dairy products from their diets.
Thus, it is important for them to meet their calcium needs using alternative
calcium sources.
Calcium is present in a wide range of foods other than dairy products.
Absorbable calcium is present in leafy green vegetables, nuts, seeds, tofu
and dried fruit. Most flour is fortified with calcium carbonate so cereals
can also be a good source. Although most grains are not high in calcium
(unless fortified), they do contribute calcium to the diet because they
are consumed frequently. Additionally, there are several calcium-fortified
food sources presently available. Hard water may also provide calcium.
Meat is a poor source of calcium. In fact, the presence of phosphoric acid
(component of DNA etc in body cells) in a non-vegetarian diet can lead
to osteoporosis because phosphoric acid is eliminated from body by formation
of calcium phosphate, a water-soluble salt. Carbonated drinks also deplete
calcium levels in the body. So, a regular diet of “burger and cola” can
lead to early manifestation of osteoporosis as well as obesity. This combination
must contribute to increases in falls fractures.
Calcium balance can be affected by a range of other factors. Vitamin D
is essential for absorption of calcium from the gut. This is because calcium
is transported into the body by a special carrier protein which requires
vitamin D for its synthesis.
A number of substances can inhibit the absorption of calcium. Phytic acid,
found in bran, whole cereals and raw vegetables, is one of these. Uronic
acid, a component of dietary fibre, and oxalic acid, found in certain fruits
and vegetables, can also bind calcium. However, diets habitually high in
these acids are not thought to have a major effect on calcium absorption.
Saturated fats found in milk lessen calcium absorption. So good quality
advice is particularly important to the following additional groups of
people:
· Pregnant women
— because calcium absorption from the gut increases
during pregnancy and no additional calcium is generally needed (pregnant
adolescents are an exception to this, having particularly high calcium
needs)
· Breast feeding women
—
because they need an extra 550mg of calcium (a lactating women can lose
up to 300mg a day in breast milk)
· The elderly
— because calcium absorption decreases with age
Snacking with nuts and dried fruits, modifying diet to take into account
the above advice, and avoiding carbonated drinks might be a healthier option
for children and adults.
Hemant Patel
Brentwood, Essex |
The
Pharmaceutical Journal