WATER

SOLUBLE
VITAMINS
 INTRODUCTION

The water-soluble vitamins are vitamin C or

ascorbic acid and the B-complex vitamins.
Vitamin C is the most easily destroyed of all the
vitamins. It is the "fresh foods" vitamin since it
occurs in growing parts of plants. The B-
complex vitamins important in human nutrition
are: thiamin, riboflavin, vitamin B⁶, vitamin B¹²,
niacin, folic acid, inositol and biotin
 GENERAL CHARACTERISTICS
Water soluble vitamins are known to combine
with specific enzymes.( 1.) There is very little
storage of water soluble vitamins in the body.(
2.) They occur in bound form which is inactive.
(3.) Parasitic organisms in the gastrointestinal
tract need B-vitamins also and they compete
with absorption of these vitamins.( 4.) Early
deficiency signs are the same for the B-
vitamins, but advanced.
 A. ASCORBIC ACID
Forms and Measurement : Vitamin
C or ascorbic acid is also known as
antiscorbutic vitamin because it
prevents the nutritional disease
SCURVY.
 FUNCTIONS

Vitamin C is needed in the formation

and maintenance of intercellular
cementing substance which is the
"binder" that holds cells as well as to
the cellular fluid which bathes and
nourishes them.
 FOOD SOURCES
The richest source for vitamin C is the Puerto Rico
cherry, called acerola In the Philippines source fortunate
to have a variety of tropical rings that are excellent
sources, like guava, papaya, datilis, (small cherries),
oranges, dayap (lime) and kamatsile kalamansi (native
lemons), melons, and berries. Table 12-1 lists of local the
ascorbic acid content of local fruits.. There are also
vegetables rich in vitamin C, especially if eaten raw, like
the leafy greens, peppers, and tomatoes. Three servings
of fruits a day and two to three kinds of vegetables, will
be adequate for a person's vitamin C supply. Check
Appendix A and B for recommended serving portions.
 B. THIAMIN(Vitamin B¹)
Functions:
Thiamin is an integral part of the
coenzyme factor. thiamin pyrophosphate
or TPP, which is needed for carbohydrate
metabolism. Helps maintain good
appetite, good muscle tone, especially of
the gastrointestinal tract, and for normal
functioning of the nerves.
 UTILIZATION
Thiamin is stable in dry heat,
but easily destroyed by alkalis
and sulfites. Its absorption is
facilitated by an acid medium.
Is concentrated in the liver,
brain, heart, and muscles.
 FOOD SOURCES
Outstanding food sources are lean pork, pork liver and other
glandular organs of pork and some shellfish. Next in line as
excellent sources are liver and organ meats of other animals,
egg yolk, unpolished rice, whole grains, legumes (like "mongo,"
“Kadyos ," soybean) and nuts. The enrichment or fortification of
cereals like rice and wheat flour requires additional thiamin.
Note the difference in the nutrient values of enriched vs.
unenriched rice or noodles in Table 12-2. Dried yeast, rice bran
and wheat germ are concentrated natural sources. They can be
used to enrich food staples or as added ingredients but not as
common foods eaten as such.
 C. RIBOFLAVIN
Functions:
As an essential component of coenzymes, flavin
mononucleotide (FMN) and flavin adenine
dinucleotide (FAD), riboflavin is essential for
protein, fat and carbohydrate metabolism. It is
also needed for the conversion of tryptophan to
niacin. It helps maintain healthy skin, tongue
and mouth.
 Utilization

Riboflavin is easily destroyed by

light, irradiation and alkali. It is
absorbed through the small
intestines after it is activated by
phosphorylation.
 FOOD SOURCE
The best animal sources are cheese, milk, eggs, liver
and other glandular organs, and lean meats. Plant
sources with high B2 values are whole grain,
legumes, leafy green vegetables and seaweed. In
the USA, riboflavin is added in flour enrichment. The
RDA Table for Filipinos shows a range of 0.5 (for
infancy) to 1.5 mg for lactation and this can be met
by following the suggested servings of the "Guide
to Good Nutrition."
 D. NIACIN
Functions:
Niacin acts as hydrogen and electron
acceptors, a biochemical reaction
important in energy metabolism (aerobic
and anaerobic oxidation of glucose), fatty
acid synthesis/oxidation and protein
synthesis/catabolism. Niacin is also
needed for photosynthesis is plants and
carbon dioxide fixation in animal cells.
 Utilization

Niacin is the most stable of the

water soluble vitamins. It is
stored in tissues in limited
amounts depending on tissue
depletion or saturation.
 E. PYRIDOXINE
Functions:
All these forms are converted to the
active co-enzyme factor pyridoxal
phosphate, which is involved in amino
acid metabolism. It catalyzes urea
production, synthesis of essential fatty
acids, and the conversion of niacin from
tryptophan.
 Utilization
Pyridoxine is readily absorbed in
the intestines and is circulated in
the blood as the active co-
enzyme, pyridoxal phosphate.
Intestinal synthesis, although
present in man, is not
significant.
 F. PANTOTHENIC ACID
Functions:
As an important component of coenzymes A
pantothenic acid is needed for "active acetate"
or acetylation reactions oxidation of keto-acids
and fatty acids synthesis of lipids acetylcholine
and porphyrin ring. Therefore, pantothenic acid
is essential for carbohydrate, protein and fat
metabolism as well as for the maintenance of
normal growth, healthy skin and integrity of the
central nervous system
 Utilization

Pantothenic acid is readily absorbed in

the small intestines. It is stored to a
limited extent in the liver and kidney.
It occurs in the blood and tissues in
bound form (as coenzyme A). There is
bacterial synthesis in the intestines.
 BIOTIN Functions:

The Chief role of biotin is as a

coenzyme factor in carbon dioxide
fixation. Together with active acetate
(CoA), it helps in the synthesis of
purines, fatty acids and carboxylation
reactions..
 Utilization
Biotin is not readily absorbed
compared to other B vitamins. It is
bound to protein in foods and is
released during digestion. Avidin,
protein is raw egg white, binds biotin
and renders it unavailable.
 CHOLINE
For over a hundred years, choline has
been known to be a constituent of
important substances in animal cells.
However, biosynthesis in man has not
been established.
 FUNCTIONS
Functions Choline is the major source of methyl-
(CH3-) group in the diet. Its metabolism is closely
related to that of folate and methionine as methyl
donors. The most important biological role of
choline in several animal species including man is as
a lipotropic agent, i.e., it mobilizes fat and prevents
fatty liver. Choline is needed for fat transport as a
constituent of phospholipids, namely: lecithin,
cephalin and sphingomyelin.
 Requirement or Allowance
The Committee on Nutrition of the American Academy
of Pediatrics recommends the inclusion of choline for
infant formulas to contain at least 7 mg choline per
100 Kcal.
Food Sources :The richest food source for choline is
egg yolk: other good sources are liver, brain, kidney,
heart, meats, legumes and nuts, yeast and wheat
germ. The last two are supplements or ingredients
rather than common foods.