content and its percentage of the daily adequate
intake (AI) amount.
Three forms of calcium are commonly available
as dietary supplements: calcium carbonate, cal-
cium citrate, and calcium phosphate. However,
many doctors believe the form of calcium matters
far less than maintaining adequate intake of cal-
cium. Individuals have varying tolerances and
responses to the different forms of calcium supple-
ments. Many doctors recommend calcium carbon-
ate in the form of chewable antacid tablets as the
most available, easiest to take, and least expensive
calcium supplement product. Because numerous
factors influence how much calcium the gastroin-
testinal tract absorbs, health experts recommend
obtaining as much calcium as possible through
dietary sources with calcium supplementation to
make up the difference. Total calcium consump-
tion that exceeds 2000 milligrams (mg) a day does
not provide any added benefit and may cause
health problems due to excessive calcium.
The body also requires vitamin D to absorb
dietary calcium. The primary sources of vitamin D
are sunlight and dietary supplements. The body
can synthesize (make) as much vitamin D as it
needs with adequate SKINexposure to sunlight.
However, many people do not get enough sun-
light. SUN PROTECTIONproducts, necessarily applied
to protect against SUNBURN block the ultraviolet
rays that activate vitamin D synthesis. As well,
there is not adequate ultraviolet light exposure
during the winter months for people who live in
the northern hemisphere—in the United States,
above a line roughly drawn from San Francisco to
Boston. Because of these factors, most calcium-
fortified foods also contain supplemental vitamin
D. Inadequate vitamin D causes softness of the
bones—RICKETS in children and OSTEOMALACIA in
adults—regardless of calcium intake because the
body cannot absorb calcium without vitamin D.
Though insufficient calcium intake is by far the
more significant health issue because of the effect
it has on bones, excessive calcium consumption
has potentially serious adverse effects on the body
systemically. Excessive calcium can cause ARRHYTH-
MIA (irregularity in the HEART RATE), MUSCLE
cramps, kidney stones (NEPHROLITHIASIS), and NERVE
disturbances.
See alsoCRAMP;DIET AND HEALTH; EXERCISE AND
HEALTH; HYPERCALCEMIA; HYPERPARATHYROIDISM; HYPO-
CALCEMIA; HYPOPARATHYROIDISM; MINERALS AND
HEALTH; PARATHYROID GLANDS; SMOKING AND HEALTH;
VITAMINS AND HEALTH.carpal tunnel syndrome A collection of symp-
toms resulting from compression of the median
NERVEas it passes through the carpal tunnel, a nar-
row channel in the carpal bones of the wrist. The
ligaments that form the carpal tunnel can become
irritated and inflamed, constricting the median
nerve and the tendons in the area. The median
nerve supplies the inside of the hand, the thumb,
and the first three fingers (the ulnar nerve sup-
plies the outside of the hand and the little finger).
Compression of the nerve affects sensation and
function in the hand.Symptoms and Diagnostic Path
Symptoms of carpal tunnel syndrome progress
gradually over months to years. They may include- tingling
- numbness
- weakness
- loss of ability to use the thumb and first two or
three fingers - PAINthat shoots from the hand up the forearm
Some people also experience perceptible
swelling and tenderness to touch over the wrist.
Symptoms are generally intermittent at the onset
and progress to occur more frequently and have
greater intensity. The diagnostic path includes tests
of the hand and wrist that are able to bring on or
intensify the symptoms. The doctor may order
electromyogram (EMG) and nerve conduction
studies for further diagnostic information.Treatment Options and Outlook
Treatment efforts attempt to manage symptoms
conservatively, with measures such as NONS-
TEROIDAL ANTI-INFLAMMATORY DRUGS(NSAIDS), injec-
tion of a corticosteroid, and splinting. When fluid
retention (edema) is a factor, diuretic medications
(“water pills”) may help. Some people experiencecarpal tunnel syndrome 315