FOLIC ACID
FOLIC ACID SUPPLEMENTS ARE MORE EFFECTIVE THAN INCREASED
DIETARY FOLATE INTAKE IN ELEVATING SERUM FOLATE LEVELS
In 1992 the Department of Health advised that to prevent
the first occurrence of a neural tube defect all women should
increase their folate consumption by 400micrograms in the periconceptional
period. This was to be achieved by increasing consumption
of folate-rich foods or taking a daily 400micrograms folic acid
supplement. However, a recent study found that only one-quarter
of women with an uncomplicated obstetric history and 51%
with a complicated obstetric history took supplements for
the recommended time period. Dietary modification was found
to be extremely unusual. Serum analysis demonstrated that
intake of folic acid supplements provides a greater elevation
in serum folate levels than dietary food intake.
This suggests that dietary manipulation is an ineffective
strategy and that efforts would be better focused on increasing
supplement intake at a clinically important time. More effective
education strategies are required, and since approximately
one-third of pregnancies are unplanned, fortification of
foods with folic acid is warranted.
Elkin, A.C. and Higham, J.
BJOG 2000, 107 (2) 285-9
NEURAL TUBE DEFECTS AND PERICONCEPTIONAL FOLIC ACID
Authors of this retrospective study assessed whether there
had been any change in the incidence of neural tube defects
since 1992, when the Expert Advisory Group in the UK recommended
that women who were trying to conceive should take 0.4mg
folic acid per day.
They found that before 1992 there was a significant drop
in the incidence of neural tube defects, but that since
1992 the rates of decline have stabilised and become significantly
less rapid than before 1992. The number of prescriptions
of folic acid dispensed increased between 1990 and 1996,
and over the counter sales increased between 1990 and 1994
and declined in 1995-6.
The authors speculate that perhaps women may not be taking
supplements at the right time, or the dose may be too low,
or the supplements may not be taken by those at the highest
risk, as periconceptional supplementation with folic acid
has been shown to be effective in randomised controlled
trials.
Kadir et al
BMJ no 7202 10th July 1999
A PROSPECTIVE STUDY OF FOLATE INTAKE AND THE RISK OF BREAST
CANCER
Low folate intake has been associated with higher risk
of colon cancer in epidemiologic studies, particularly in
the presence of alcohol consumption. Alcohol is a known
folate antagonist and thus could plausibly increase the
requirement for folate intake. Therefore, a study was carried
out to assess the association between folate intake and
risk of breast cancer, and whether higher folate intake
may reduce excess risk among women who consume alcohol.
A total of 3483 cases of breast cancer were documented.
Total folate intake was not associated with overall risk
of breast cancer. However, among women who consumed at least
15 G/D of alcohol, the risk of breast cancer was highest
among those with low folate intake. This risk was strongest
among women with total folate intake of less than 300?g/d.
Current use of multivitamin supplements, the major source
of folate, was associated with lower breast cancer risk
among women who consumed at least 15 g/d of alcohol. Thus,
the findings suggest that the excess risk of breast cancer
associated with alcohol consumption may be reduced by adequate
folate intake.
Zhang, S. et al
J.A.M.A. 1999, 281 (17) 1632-7
HEARING LOSS IN ELDERLY ASSOCIATED WITH VITAMIN B12 AND
FOLATE DEFICIENCY
Scientists tested the hypothesis that age-related hearing
loss may be associated with low blood levels of vitamin
B12 and folic acid. They carried out a clinical trial involving
the screening of 55 elderly women. Results showed consistently
that poor hearing is linked with low blood concentrations
of vitamin B12 and folate.
AM. J. CLIN. NUTRIT. 1999, 69, 3, 564-71
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
THE EFICACY OF FOLIC ACID AND FOLINIC ACID IN REDUCING
METHOTREXATE GASTROINTESTINAL TOXICITY IN RHEUMATOID ARTHRITIS
A study was carried out to determine the efficacy of folic
acid and folinic acid in reducing the mucosal and gastrointestinal
(GI) side effects of low dose methotrexate (MTX) in patients
with rheumatoid arthrits (RA). Out of the trials which met
the inclusion criteria, the total sample included 307 patients
of which 147 were treated with folate supplementation, 67
patients with folic, and 80 with folinic acid. A 79% reduction
in mucosal and GI side effects was observed for folic acid
[OR=0.21], and for folinic acid a clinically, but not statistically
significant reduction of 42% was found [OR=0.58]. No major
differences were found between low and high doses of folic
or folinic acid. The results, therefore,support the protective
effect of folate
supplementation in reducing MTX side effects related to
the oral and GI systems.
Ortiz, Z. et al.
J. RHEUMATOL. 1998, 25 (1) 36-43
