NUTRITIONAL REQUIREMENTS DURING PREGNANCY
The RDA for an expectant mother is given in list :
ICMR Recommended dietary allowances for an expectant mother
Nutrient in Energy
Normal Adult Woman Vs Pregnant Woman
Sedentary 1875 2175
Moderate 2225 2525
Heavy 2925 3225
Protein (g) 50 65
Fat (g) 20 30
Calcium (mg) 400 1000
Iron (mg) 30 38
Retinol (mg) 600 600
b carotene (mg) 2400 2400
Sedentary 0.9 1.1
Moderate 1.1 1.3
Heavy 1.2 1.4
Sedentary 1.1 1.3
Moderate 1.3 1.5
Heavy 1.5 1.7
Sedentary 12 14
Moderate 14 16
Heavy 16 18
Pyridoxine (mg) 2.0 2.5
Ascorbic acid (mg) 40 40
Folic acid (mg) 100 400
Vitamin B12 (mg) 1 1
Energy requirement during pregnancy is increased
because of the additional energy required for
growth and activity of foetus
growth of placenta and maternal tissues
increase in maternal body size
steady rise in BMR
For a reference Indian woman (ICMR 1990)
weighing 50kg, the total energy cost of pregnancy has been estimated to be
73000 k.cal. This includes the energy required for deposition of 4 kg of body
fat (36000 k.cal) to be utilized later during lactation. Considering the
increased energy demand during lactation and beneficial effect of increased
energy intake on birth weight of infants and also protein sparing action, an
additional intake of 300k.cal.per day during pregnancy is recommended.
An additional protein intake of 15g/day i.e. a total of 65g is
recommended. The additional protein is essential for
growth of the foetus
development of placenta
enlargement of uterus,mammary gland
increased maternal blood volume
formation of amniotic fluid
preparation for labour, delivery, post partum period and lactation by
ICMR expert committee has suggested an intake of 30g of visible fat/day
during pregnancy. This is based on studies indicating that linoliec acid
requirements during this stage is 4.5 percentage of total energy. Of this, some
of the essential fatty acid needs are met with by the invisible fat. Therefore
an intake of 30g of visible fat has been suggested to meet the essential fatty
The calcium requirement for an adult woman is 400mg/day. During
pregnancy the need increases to 1000mg/day.
The additional calcium is needed for the growth and development of bones
as well as teeth of the foetus and also for the protection of calcium resources
of the mother to meet the high demand of calcium during lactation.
The amount of calcium deposited in the full grown foetus is around 30g.
Therefore an intake of 1g calcium per day which meets the needs of the mother
and the additional needs of pregnancy has been recommended by the ICMR.
Inadequate intake of calcium results in the mobilization of calcium from mother
bones resulting in demineralization of maternal bones and osteoporosis.
The requirement of iron increases from 30mg/day to 38mg/day during
The increased requirement of 8mg/day is due to
expansion of maternal tissues including red cell mass, iron content of
placenta and blood loss during parturition.
to build the iron store in foetal liver to last for atleast 4-6 months after
birth. This is because the baby's first food milk is deficient in iron.
Generally infants are born with a high level of iron, 18-22g/ 100ml.
Due to increase in BMR, iodine needs are also enhanced during pregnancy.
Deficiency of zinc adversely affects the outcome of pregnancy. Apart
from being a component of insulin and enzyme systems, it also participates in
the synthesis of DNA and RNA, playing a significant role in reproduction. Hence
zinc deficiency leads to foetal mortality, foetal, malformations and reduced
intra uterine growth rate. The risk of LBW babies doubles and preterm delivery
increases three times due to low zinc intake during pregnancy.
The increase in extra cellular fluid increases sodium requirement. Hence
restriction in diet may cause biochemical and hormonal changes.
When sodium level in blood drops
(hyponatraemia), the kidney produces hormone renin which causes increased
retention of sodium making it unavailable for normal body processes. When the system
is overtaxed it results in sodium deficiency causing increased risk of
eclempsia, prematurity and low birth weight infants. Normal sodium intake
without restriction is advised during pregnancy.
restricted when there is oedema or hypertension.
Vitamin A requirements during pregnancy have been computed based on the
vitamin A content of liver of the newborn. The additional intake works out to
throughout pregnancy. Since this constitutes a very small fraction of the RDA
for normal women, no additional allowance during pregnancy is suggested.
is essential as it enhances maternal calcium absorption. Its active form
calcidiol and calcitriol can pass through placenta with ease and help in calcium
metabolism of foetus. Since Vitamin D can be synthesised in adequate amounts by
simple exposure to UV rays no recommendation for vitamin D has been made.
Other fat soluble vitamins
Vitamin K is required for synthesis of prothrombin which is essential
for normal coagulation of blood. A liberal vitamin K level in the mother's
blood proves helpful in preventing neonatal haemorrhage. Hence it has become a
routine to administer natural form of this vitamin by injection either to the
mother before delivery or to the neonate soon after birth.
Thiamine, Riboflavin, Niacin
The RDA for thiamine, riboflavin and niacin is estimated on the same
basis as for a normal adult woman ie., 0.5mg/1000 kcal, 0.6mg/ 1000k.cal and
6.6mg/1000k.cal respectively. As the energy requirement increases during
pregnancy, the requirement of these vitamins also increases correspondingly.