Abstract:
Epidemiological studies indicated that vitamin A status is associated with plasma
fibrinogen levels. It has been shown that Africans have high plasma fibrinogen levels
compared to Europeans, probably contributing to their high risk for stroke. In this study
the hypothesis that increased intakes of vitamin A will lower plasma fibrinogen levels,
has been examined. The study formed part of a clinical intervention trial under controlled
conditions to examine the effects of vitamin A fortified sugar on plasma fibrinogen of
African females aged \3-25 years.
The methodology included questionnaires determining demographic profile, food
consumption patterns and compliance to fortified sugar consumption. Measurements
included anthropometric measurements and double baseline biochemical measurements
on 95 subjects in the randomly selected sample population. The sample population was
randomly divided into an experimental (n=46) group consuming fortified sugar (80 IU
vitamin A per gram sugar), and a control group (11=49) consuming non-fortified sugar.
Measurements were repeated after 4, 8 and 12 weeks of sugar consumption. Plasma
fibrinogen levels were determined by the Dade Behring - Multifibren® U method. The
method is a modification of the Clauss method.
The baseline measurements of plasma fibrinogen showed that 5.1 % of respondents had a
fibrinogen level of < 2.71 gil, 83.8% a fibrinogen level 2.72 - 3.30 gil and 11.1 % of
respondents had a fibrinogen level> 3.30gll.
Baseline measurements of serum vitamin A indicated that 12% of respondents had a level
of<30 flgldl, 33.7 % a level of30-40flgldl, 38.6% a level of40-50flgldl and 15.7% of the
respondents had a serum vitamin A level of>50flgldl.
During the experimental period, the subjects consumed approximately 60g sugar per day,
providing an additional 4800 IU or 1446 flg RE vitamin A per day to the experimental
group. The results indicated that mean plasma fibrinogen levels of the experimental subjects
were significantly lower than the baseline results (2.8t gIL) after 4 weeks (2.64 gIL) and
8 weeks (2 .65 giL). However, levels increased and returned to baseline levels at week 12
(2 .84 giL). The experimental subjects showed an increase in body weight at week 12, and
it is speculated that this increase could have been responsible for the increase in plasma
fibrinogen.
In conclusion the study confirmed that by the intake of fortified sugar providing
additional vitamin A in the diet of these African women, the plasma fibrinogen levels
were significantly decreased at 4 and 8 weeks. It is further recommended that the
influence of vitamin A on fibrinogen should be examined in subjects with raised
fibrinogen and decreased vitamin A levels.
