CALCIUM
CALCIUM CARBONATE AND THE PREMENSTRUAL SYNDROME - EFFECTS
ON PREMENSTRUAL AND MENSTRUAL SYMPTOMS
A prospective, randomised, double-blind, placebo-controlled,
parallel-group, multicentre clinical trial was conducted
to evaluate the effect of calcium carbonate on the luteal
and menstrual phases of the menstrual cycle in pre-menstrual
syndrome. Symptoms were documented over 2 menstrual cycles
with a daily rating score that had 17 core symptoms and
4 symptom factors (negative affect, water retention, food
cravings and pain). Participants were randomly assigned
to receive 1200 mg of elemental calcium per day in the form
of calcium carbonate or placebo for 3 menstrual cycles.
There was no difference in age, weight, height, use of oral
contraceptives, or menstrual cycle length between treatment
groups. During the luteal phase of the treatment cycle,
a significantly lower mean complex symptom score was observed
in the calcium-treated group for both the second and third
treatment cycles. By the third treatment cycle calcium effectively
resulted in an overall 48% reduction in total symptom scores
from baseline compared with a 30% reduction in placebo.
In addition, all 4-symptom factors were significantly reduced
by the third treatment cycle.
Thus, calcium supplementation is a simple and effective
treatment in pre-menstrual syndrome, resulting in a major
reduction in overall luteal phase symptoms.
Thys-Jacobs, S. et al
AMER. J .OBSTET. GYNECOL. 1998, 179 (2) 444-52
CALCIUM FOR HYPERTENSION
A double-blind randomised placebo-controlled trial took
place involving 116 adolescents to determine whether an
increased intake of calcium can lead to a reduction in blood
pressure. Subjects were given 1.5g/day of calcium or placebo.
Results confirmed that there was a decrease in diastolic
blood pressure in the group receiving a calcium supplement.
The effect was greater in those whose diets were low in
calcium.
AM. J. CLIN. NUTR. 1998, 68 (3) 648-655
MODULATION OF ABNORMAL COLONIC EPITHELIAL CELL PROLIFERATION
AND DIFFERENTIATION BY LOW-FAT DAIRY FOODS
Colon cancer claims 134,000 victims and causes about 55,000
deaths each year in the United States. Epidemiological evidence
suggests that dietary levels of calcium and vitamin D intake
are inversely related to the incidence of colon cancer.
Supplementary dietary calcium inhibits colonic epithelial
cell proliferation and cytotoxicity of faecal water and
colonic tumour formation.
A study was carried out, therefore, to determine whether
increasing calcium intake via dairy products alters colonic
biomarkers toward normal. The trial subjects had a history
of polypectomy for colonic adenomatous polyps. Low-fat dairy
products containing up to 1200 mg/d of calcium were used
and subjects were randomised to 4 strata by diet (control
vs. higher calcium) and age (<60 vs. >60). It was
found that during 6 and 12 months of treatment there was
reduction of colonic epithelial cell proliferative activity,
reduction in size of the proliferative compartment, and
restoration of acidic mucin, cytokeratin AE1 distribution,
and nuclear size, toward that of normal cells. In contrast,
control subjects showed no differences from baseline values
at 6 and 12 months.
Thus, increasing the daily intake of calcium by up to 1200
mg via low-fat dairy food in subjects at risk for colonic
neoplasia reduces proliferative activity of colonic epithelial
cells and restores markers of normal cellular differentiation.
Holt, P.R. et al
J.A.M.A. 1998, 280 (12) 1074-9
MORE EFFORT NEEDED TO HALT OSTEOPOROTIC BONE LOSS
At a recent British Society for Rheumatology meeting it
was announced that steroid-induced osteoporosis is a problem
that is not being effectively tackled. About 0.5% of the
general population is receiving long-term steroid therapy,
but a survey showed that only about 14% had taken some form
of preventative treatment for bone loss. It was reported
that the C-terminal (CTX) and N-terminal (NTX) peptides
of type-1 collagen were helpful biochemical markers for
prediction of bone loss in osteoporosis. CTX and free deoxypyridinoline
have also proved highly predictive of hip-fracture rate
in osteoporosis, independent of bone mass. It was suggested
that patients on prednisolone 7.5 mg or more per day for
6 months or longer should be targeted for prophylactic therapy
for bone loss. Vitamin D and calcium supplementation should
be considered in all patients.
Clark, S.
LANCET 1998, 351 (9112) 1335
VITAMINS ASSOCIATED WITH LOWER COLON-CANCER RISK
A recent study has shown that supplements of of multivitamins
and vitamin E are associated with a lower risk of colon
cancer. American researchers assessed the frequency, duration,
and daily dose of individual vitamin supplements and multivitamins,
for a ten year interval ending two years before diagnosis
of cancer. After controlling for other predictors of colon-cancer
risk such as intake of dietary vitamins, alcohol, and fibre,
the risk of colon cancer was lower in men and women who
took supplements of vitamins A, C, E, folic acid, calcium,
and multivitamins. But the association was strongest for
vitamin E and multivitamins: people who used multivitamins
daily for the entire 10-year interval had half the risk
of those who had not taken multivitamins. Those who averaged
200 IU or more of vitamin E per day for the 10 years had
a 57% risk reduction compared to non-users.
Macready, N
THE LANCET 1997, 350 (9089) 1452
EFFECT OF CALCIUM AND VITAMIN D SUPPLEMENTATION ON BONE
DENSITY IN MEN AND WOMEN 65 YEARS OF AGE OR OLDER
A study was carried out to determine the effects of three
years of dietary supplementation with calcium and vitamin
D on bone mineral density, biochemical measures of bone
metabolism, and the incidence of nonvertebral fractures
in 176 men and 213 women 65 years of age or older. They
received either 500mg of calcium plus 700 IU of vitamin
D (cholecalciferol) per day or placebo. The mean changes
in bone mineral density in the calcium-vitamin D and placebo
groups were as follows:
femoral neck, +0.50 and -0.70%, respectively; spine, +2.12
and +1.22%;
total body, +0.06 and -1.09%.
The difference between the calcium-vitamin D and placebo
groups was significant at all skeletal sites after one year,
but it was significant only for total-body bone mineral
density in the second and third years.
Dawson-Hughes, B et al.
N. ENGL. J. MED. 1997, 337 (10) 670-6
