The Importance of Calcium in the Diet
Calcium is absorbed in the small intestine; this process is
dependent on vitamin D. To provide the rigid structure of the
skeleton calcium is vital, around about 3lb of the body's weight
is calcium, 99 per cent being in the teeth and bones. It is
important in growing children to help bones grow and the elderly
as the ability to absorb calcium becomes impaired with age.
Together with magnesium it is needed for nerves and muscles to
function properly. It also helps to maintain the right
acid/alkaline balance and blood to clot. An adult needs a daily
calcium intake of between 700 and 1000mg. Those at risk of
osteoporosis may need as much as 1500mg a day. This protection
is boosted when combined with linoleic acid from evening
primrose oil. Calcium and phosphorus work together on a ratio of
two to one for healthy teeth and bones and calcium and magnesium
work together for cardiovascular health. The two most deficient
minerals in a women's diet are calcium and iron.
Calcium supplements have shown to protect against pre-eclampsia
which is high blood pressure in pregnancy. It is a good idea to
increase calcium consumption during the last three months of
pregnancy and the first few months of lactation to ensure that
the baby get sufficient amount of calcium to help bone
development and growth. If the baby doesn't get enough calcium
from its mother, it will be withdrawn from the mothers bones,
possibly leading to bone disease in the future.
Signs of calcium deficiency are rickets, osteomalacia and
osteoporosis.
Calcium like sodium and potassium contribute to both
extracellular and intracellular cell environment. Calcium is
also needed as intercellular cement to keep the cells of the
body together. It also controls fluid to allow enzyme reaction
to take place. Calcium is vital for the contraction of muscle.
The brain sends nerve impulses that release calcium in the
muscle which triggers muscle reactions. Calcium also helps to
control cholesterol.
Calcium helps in the process of secretion, bile, pancreatic
fluid, gastric, intestinal, hormonal and mucous all rely on
calcium to move the small droplets through the cells boundaries
and cell walls.
The AMP (adenosine monophosphate) is calcium dependent. This
maintains the balance of proteins in the body.
Calcium is also needed in the release of neurotransmitter. These
are vital for a proper functioning nervous system.
Calcium is one of the 'buffers' in blood that helps to keep the
levels of acid/alkaline. Calcium levels in the blood are
affected by hormones. If levels drop then Tetany could occur;
this is a condition that causes tremors and involuntary
contractions of the muscles.
Osteoporosis, which means "porous bones", is at epidemic
proportions particularly in women after the menopause. It is a
painful and potentially crippling disease which is due to the
loss of calcium in the bones. By the age of fifty up to 25 per
cent of the skeleton could be missing due to Osteoporosis, this
can increase the risk of bone fractures, loss of height and
formation of a "dowager's hump" all due to the soft and thinning
bones. This will affect one in three women and one in twelve men
by the age of seventy.
The conventional explanation of why Osteoporosis affects women
of a certain age more than men is that once a women stops
menstruating she produces only a small amount of the oestrogen
which helps to keep calcium in her bones. This is why women are
recommended to take hormone replacement therapy (HRT). This is
not the case as research has shown that Progesterone stimulate
osteoblasts to produce new bone and that by taking Progesterone
it increases bone density by four times, oestrogen which
stimulates osteoclast cells only stops the loss of old bone.
A women stops ovulating in the time before and after the
menopause. Even though the body still produces a little amount
of oestrogen if no ovum is released then no progesterone is
produced. Scientists now believe that it is the deficiency of
progesterone not oestrogen that is precipitating osteoporosis.
This is not the only factor in the cause of osteoporosis; diet
is also a strong factor which is why it is uncommon in some
cultural groups. The lack of calcium in the diet is thought not
to have a huge baring on osteoporosis, in fact the Bantu tribes
of Africa have on average a calcium intake of 400mg and their
women suffer little osteoporosis whereas the Eskimos have a
substantial higher intake of calcium in their diet but their
women suffer from high incidents of osteoporosis. The problem
seems to be too much dietary protein.?
The Eskimos have more protein in their diet than the Bantu
tribes. Protein-rich foods are acid-forming. The body cannot
tolerate acid level changes and it uses the alkaline agents -
sodium and calcium to neutralise the acid effect. When all the
sodium reserves are used up by the body it takes calcium from
the bones. This is why a high protein acid forming diet leads to
calcium deficiency and may also be the primary cause of
osteoporosis. This may well explain why vegetarian women suffer
less from osteoporosis. In fact vegetarians in general need less
calcium than those who eat meat because of the reduce intake of
protein.
Omega 3 and 6 fatty acids which are found in fish oil and
evening primrose oil if taken in large doses increase the
absorption of calcium from the gut like vitamin D does. Not only
do they increase calcium absorption but they also reduce calcium
loss in the urine. PUFAs prevent the abnormal deposition of
calcium in soft tissue and increase calcium levels in bones.
PUFAs can help with the bone loss at menopause.
In summary, calcium is a very important mineral in the diet
especially with women at menopausal age. It can stop the onset
of osteoporosis and reduce bone loss and fragility. It is also
important for pregnant women, growing children and the elderly.