Vitamin B-Complex and Vitamin C—the water soluble vitamins

Water soluble vitamins, though very vital, are easily excreted through urine. Eating healthy food and supplementation is the best way to meet our daily requirements

Natural sources of viaminsVitamins are the way to health. In A D E K: The vital vitamins, we discussed the role fat soluble vitamins play in our body. In this article we discuss the functions water soluble vitamins, its sources and deficiency symptoms.

Water soluble vitamins get dissolved in water easily and therefore need to be supplemented on a regular basis. The advantage: if present in excess, they get eliminated from our body through urine.

Water soluble vitamins include vitamin C, and B complex [8 types].

Vitamin C – Ascorbic acid

Our body can not synthesise this vitamin and therefore supplementation is extremely important.


Vitamin C is essential for healthy collagen [connective tissue protein], immune system functions, formation of bones and teeth and building strong blood vessels. It is a powerful antioxidant and facilitates better iron absorption.

Deficiency symptoms

The most common deficiency of this vitamin is ‘scurvy’. Symptoms include tooth loss and bleeding gums. Scurvy is very rare, but is seen in sailors or people who do not consume their daily requirement. One may also experience depression, irritability, weight loss or general fatigue due its deficiency.


The best sources are strawberries, broccoli, amla [Indian gooseberry], peppers, citrus fruits, lemon, tomatoes, and green leafy vegetables. This vitamin gets readily oxidised [evaporated in the air] and hence it is extremely important to cut these fruits or vegetables just before consumption.

B complex vitamins

B complex vitamins are of eight types. These vitamins are essential for conversion of food to energy. They do not provide the energy that comes from macronutrients, but are essential helpers in maintaining good health. They also help you to keep your heart healthy along with maintaining your immune system and fighting stress.

Vitamin B1 – Thiamine

This vitamin helps convert the carbohydrates from our food to energy.


It helps build energy and aids fighting fatigue. Thiamine is required for the normal functioning of our immune system and muscle strength. It also helps in conduction of nerve impulses.

Deficiency symptoms

Deficiency leads to reduced mental alertness, and body fatigue. A severe deficiency known as ‘Beri-Beri’ may affect the nervous system.
Beri-Beri is classified into three stages: childhood, wet and dry. Another rare deficiency of this vitamin is known as ‘Wernicke Korsakoff’ syndrome.


For vegetarians, the best sources are cereals, whole grains, nuts, oilseeds and broccoli. For non-vegetarians, it is pork, tuna, chicken breast, liver and beef.

Vitamin B2 – Riboflavin

Many people notice a peculier yellow coloured urine after taking B complex supplements. This is due to presence of riboflavin. Riboflavin is easily available through a healthy diet.


This helps metabolise carbohydrates, proteins and fats to produce energy. It also helps in maintaining good vision, healthy hair, skin and nails and is necessary for cell growth.

Deficiency symptoms

Riboflavin deficiency causes a condition known as ‘Ariboflavinosis’. The symptoms are cracked corners of the mouth [Cheilosis], oily and scaly skin along with red sore tongue; in some cases ulcers of the mouth are seen. Cataract may also occur.


The various sources are milk, eggs, mushrooms, whole grains, green leafy vegetables, yeast, liver and oily fish.

Vitamin B3 – Niacin

It exists in two forms: nicotinic acid and nicotinamide. Both these forms are readily absorbed by the small intestine and the stomach. Niacin is stored in the liver in small amounts and gets transported to the body for its daily functions. The excess is excreted through urine. Niacin is one of the most stable water soluble vitamins.


Niacin being very stable acts in any environment, be it acidic or alkaline medium or even in heat and light. The main function is to get energy from food to make neurotransmitters. Niacin also helps keep the skin and digestive system healthy.

Deficiency symptoms

Deficiency is rare as our body can make vitamin B3 with the help of the amino acid called tryptophan. In rare cases, deficiency called pellagra may occur. The symptoms are the four d’s: diarrhoea, dermatitis, dementia and death.


The most common foods containing vitamin B3 are peanuts, mushrooms, whole grains, yeast, milk, eggs [tryptophan], poultry and fish.

Vitamin B5 – Pantothenic acid

This vitamin is most stable in moist heat; but gets destroyed in dry, acidic and alkaline mediums.


Vitamin B5 is released by the coenzyme A of the food in the small intestine and is transported to the tissues for the conversion of carbohydrates, fats and proteins to energy. This helps in the synthesis of fatty acids, cholesterol, steroids and neurotransmitters.

Deficiency symptoms

Dietary deficiency occurs in conjunction with other B complex vitamins and is extremely rare. The symptoms could include headache, fatigues, abdominal cramps, vomiting, and impaired muscle coordination.


It is available in a wide variety of fruits and vegetables.

Daily requirement of B complex vitamins

Vitamin B1

  • *Children: 15 – 25mg
  • Adult male: 90mg
  • Adult female: 90mg
  • Pregnant and lactating female: 95mg

Vitamin B2

  • *Children: 0.6mg
  • Adult male: 1.3mg
  • Adult female: 1.1mg
  • Pregnant and lactating female: 1.4mg

Vitamin B3

  • *Children: 6-8mg**NE
  • Adult male: 16mg**NE
  • Adult female: 14mg **NE
  • Pregnant and lactating female: 18mg and 17mg each**NE

Vitamin B5

  • *Children: 2-3mg
  • Adult male: 5mg
  • Adult female: 5mg
  • Pregnant and lactating female: 6mg and 7mg

Vitamin B6

  • *Children: 0.6mg
  • Adult male: 1.3mg
  • Adult female: 1.3mg
  • Pregnant and lactating female: 1.9mg and 1.2 mg

Vitamin B8

  • *Children: 8-12I
  • Adult male: 30I
  • Adult female: 30I
  • Pregnant and lactating female: 30I? and 35I?

Vitamin B9

  • *Children: 150-200µg
  • Adult male: 400µg
  • Adult female: 400µg
  • Pregnant and lactating female: 600µg and 500µg

Vitamin B12

  • *Children: 0.2-1.9mcg
  • Adult male: 2.4 mcg
  • Adult female: 2.4 mcg
  • Pregnant and lactating female: 2.6mcg and 2.8lmcg

Vitamin C

  • *Children: 15-25mg
  • Adult male: 90mg
  • Adult female: 75mg
  • Pregnant and lactating female: 85mg and 120mg

*Depending on age and sex and as prescribed by your doctor/nutritionist
**NE – Niacin Equivalent

Vitamin B6 – Pyridoxine

It is available in the body in three forms: pyridoxal, pyridoxine and pyridoxamine. All forms can be converted to the active form [pyridoxal 5-phosphate]. This vitamin is not stable in heat and alkaline mediums, and therefore gets lost when cooked. Vitamin B6 is stored in muscles and gets excreted through urine.


It plays an important role in the formation of haemoglobin which carries oxygen to the blood. It also helps in maintaining blood glucose levels by facilitating release of glucose from the liver and muscle glycogen.

Deficiency symptoms

The most likely deficiency due to this vitamin could be anaemia [low haemoglobin levels]. The symptoms could be tiredness or fatigue, pale skin and eyes. Alcoholics and elderly are at risk of this vitamin deficiency.


The common sources are meat and fish, bananas, nuts, green vegetables and to some extent cereals.

Vitamin B8 – Biotin

Just like niacin, it is most stable and is absorbed in the small intestine.


Biotin is important for producing fatty acids and making energy through carbohydrates, proteins and fats.

Deficiency symptoms

Deficiency may develop mostly in infants born with a genetic defect. The symptoms could vary from dermatitis, hair loss, to neurological disorders, convulsions and impaired growth.


It is found in small amounts in eggs, nuts and oilseeds and grains.

Vitamin B9 – folic acid

It is also known as folate or folacin, which is the natural form and folic acid is the synthetic form. However, the folic acid form is more readily absorbed and available to the body.


Folate plays an important role in synthesis of neurotransmitters. It also helps maintain mood and mental functions. It also helps prevent anaemia.

Deficiency symptoms

Folate deficiency is very common. Symptoms include tiredness, fatigue, irritability and loss of appetite. If these symptoms go untreated ‘Macrocytic Anaemia’ [in which red blood cells remain in immature large form called macrocytes] may set in. In severe cases, abdominal cramps and diarrhoea may also be seen.

In infants, ‘Spina Bifida’ [failure of the spine to close properly during pregnancy] is seen due to folate deficiency. Therefore, folic acid supplementation during pregnancy becomes extremely important.


It is not found in large amounts in natural forms, but some percentage is available through legumes, green vegetables, oranges and liver.

Vitamin B12 – Cobalamine

Absorption of this vitamin requires an intrinsic factor [a protein produced by the acid producing cells of the stomach]. Most of the vitamin B12 is stored in the liver and is absorbed by the small intestine.


It helps maintain the red blood cells, prevents degeneration of the myelin sheath, and maintains normal electrical conductivity through the nerves.

Deficiency symptoms

Vitamin B12 deficiency leads to ‘Pernicious Anaemia’, which is caused by a genetic defect of the intrinsic factor, which in turn affects the folate functioning thus leading to macrocytic anaemia. This anaemia is accompanied by nerve degeneration, which if left untreated could lead to paralysis.


Egg, milk and its products, fish and poultry are the most common sources. In some countries, fortified products like B12-enriched cereals and milk/cheese/cream are also available.

Malavika Athavale
Malavika Athavale is a post graduate in Dietetics from SNDT University and a consulting nutritionist with varied experiences across clinical nutrition, individual consulting and corporate nutrition assignments. She runs her nutrition clinic in Mumbai and also conducts educational workshops.


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