Essential Nutrients |

Essential Nutrients

Different nutrients perform different functions in the body. Understanding the essential nutrients, their functions in the body, and the optimum food sources of each will help you prepare balanced meals and snacks for your children. Nutrients are classified as 'macro–' or 'micro–', based on the amount that is needed by the body. The macronutrients are carbohydrates, protein and fat; the micronutrients are vitamins and minerals.


  • Provide energy to work and play
  • Serve as the first energy source, sparing protein for other functions


  • Supports growth
  • Supports maintenance and repair of tissues
  • Provide energy
  • Help in the absorption of some vitamins
  • Help the body use macronutrients
  • Help in various body functions
  • Required for various body functions
  • Support growth and development

Carbohydrates from the daily diet should provide most of the energy the body needs. The carbohydrates category of nutrients includes:

  1. Simple carbohydrates (sugars) as they are made of small molecules. They are available from table sugar, honey, milk, fruit and any other commercial product that contains sugar.

    The intake of sugars should be limited as they are only a source of energy and do not provide any vitamins, minerals or fibre. Good dental care is also required to avoid dental caries if the intake of sugar is frequent.
  2. Complex carbohydrates (starches) are made of larger molecules. Starches are also a source of many vitamins, minerals and fibre. They are available from grain foods like wheat and rice. Food made with grains are: bread, pasta, noodles and cereals. Certain starchy vegetables such as potatoes, yams and turnips are good sources of carbohydrates.

Fibre is a very important component of the diet. It is available from complex carbohydrates. Whole grains (such as brown rice), oats, barley, whole pulses, legumes, vegetables and fruits with skin are also rich sources of fibre. Fibre helps to:

  • Keep the digestive system healthy
  • Prevent constipation
  • Bind harmful substances and remove them from the intestines
  • Maintain a healthy body weight
  • Prevent heart disease and diabetes over the long term

Protein helps in the maintenance and growth of tissues. Protein helps to build enzymes, hormones and antibodies. Adequate dietary protein is essential for your child as he is in a rapid growth phase. Refer to the table below for Singapore Recommended Daily Dietary Allowance for protein.

Protein is made up of different amino acids. These amino acids are usually classified as:

  • Essential – cannot be synthesised in the body and need to be consumed as part of the diet
  • Non–essential amino acids – can be synthesised in the body from other amino acids
The body requires 20 different amino acids of which 10 are essential for children. Protein that contains all essential amino acids is called good quality protein. It is found in animal sources like fish, eggs, meat, milk and other dairy products. These need to be included in the diets of children.


The amino acids in legumes can be complemented with protein from a cereal. For example, tofu with rice or noodles, lentils or beans and rice, peanut butter with bread, etc.

Fats are the most concentrated source of energy. They also perform other functions, helping in:

Fat in the diet
  • Absorption of the fat soluble vitamins A, D and E
  • Providing fatty acids that are structural components in the brain and eyes
Fat in the body
  • Insulation of the body's organs

Fatty acids are components of fat and are essential for brain growth.

The Table Below Shows Singapore Recommended Daily Dietary Allowances (RDDA) for Energy and Protein.


Vitamins are important to the various chemical reactions involved in digesting and absorbing (using) the food consumed. Some of the most important vitamins are:

Vitamin A
Vitamin A helps in
  • Supporting normal eye function
  • Night vision
  • Maintaining immunity
  • Keeping skin, hair and nails healthy
Vitamin A deficiency could result in
  • Reduced night vision
  • Weakened immunity
  • Dry, rough skin
Vitamin A is available from

Carrots, sweet potatoes, pumpkins, dark green leafy vegetables (such as broccoli, spinach, chye sim, kai lan), yellow and orange-coloured fruit (rock melons, papayas, mangoes), red capsicums, liver, fatty fish (sardines, salmon, tuna and mackerel), milk, egg yolks, cheese.
Vitamin D
Vitamin D helps in
  • Absorbing calcium and keeping bones healthy
  • Repairing bones
  • Healthy function of the thyroid gland
  • Regulating white blood cells that help in immunity
Vitamin D deficiency could result in
  • Rickets
  • Soft bones
  • Tooth decay
  • Muscular weakness
Vitamin D is available from

Fatty fish, fortified milk, butter, veal, beef, egg yolks, liver.
Vitamin E
Vitamin E helps in
  • Building immunity
  • Formation of blood cells
  • Promoting healthy skin and hair
Vitamin E deficiency could result in
  • Anaemia
  • Dry skin
  • Changes in heart and skeletal muscles
  • Abnormal fat deposits in muscles
  • Reduction in immunity
Vitamin E is available from

Fortified breakfast cereals, plant oils (sunflower, soy bean, corn, canola), tofu, orange-coloured vegetables (sweet potatoes, carrots), dark green leafy vegetables, broccoli, liver, egg yolks.

Vitamin B1
Vitamin B1 (thiamine) helps in
  • Enhancing blood circulation
  • Blood formation
  • Carbohydrate digestion and utilisation
  • Brain function and alertness
Vitamin B1 deficiency could result in
  • Loss of appetite
  • Weakness and feeling of tiredness
  • Heart and stomach problems
  • Body aches
Vitamin B1 is available from

Pork, liver, soy milk, fortified breakfast cereals, green peas, spinach, corn, oranges, beans, whole grain cereals (rice and wheat).

Vitamin B2
Vitamin B2 (riboflavin) helps in
  • Formation of red blood cells
  • Digestion and utilisation of carbohydrates, fats and proteins
  • Releasing energy from food
  • Maintaining healthy skin, hair and nails
  • Synthesis of some hormones
Vitamin B2 deficiency could result in
  • Burning eyes
  • Cracks in the corner of the mouth
  • Skin problems
  • Sluggishness
  • Digestive problems
Vitamin B2 is available from

Liver, dairy products (milk, cheese, yogurt), fortified breakfast cereals, eggs, dark green leafy vegetables, broccoli.

Vitamin B3
Vitamin B3 (niacin) helps in
  • Improving skin health
  • Increasing blood circulation
  • Function of the nervous system
  • Digestion and absorption of carbohydrates, proteins and fats
Vitamin B3 deficiency could result in
  • Pellagra or skin sensitivities
  • Stomach disorders
  • Tiredness
  • Skin problems
  • Aches and pains
Vitamin B3 is available from

Liver, chicken, turkey, fatty fish, beef, fortified breakfast cereals, potatoes.

Vitamin C
Vitamin C helps in
  • Keeping gums and teeth healthy
  • Wound healing
  • Maintaining good immunity
Vitamin C deficiency could result in
  • Bleeding gums
  • Joint pains
  • Scurvy
  • Slow wound healing
  • Tooth decay
  • Reduced absorption of iron
Vitamin C is available from

Citrus fruits (oranges, grape fruit), strawberries, kiwi fruit, peaches, papayas, dark green leafy vegetables, cabbage, broccoli, capsicums (bell peppers), bean sprouts, tomatoes.


Singapore Recommended Daily Dietary Allowance (RDDA) For Vitamins


Minerals are elements that come from the earth and cannot be made in the body. Most of the minerals in the diet come from the food that we eat or the water that we drink. Several minerals are needed for various body functions. Some minerals, like calcium, are required in large amounts. Others, such as manganese and selenium, are needed in very small quantities. However, all of them are important and should be included in the diet.

Calcium helps in
  • Keeping bones and teeth healthy
  • Clotting of blood
  • Normal contraction of muscles
  • Contraction of heart muscles
Calcium deficiency could result in
  • Weak bones especially in women and children
Calcium is available from

Dairy products (milk, cheese, yogurt), dark green vegetables, broccoli, salmon, tofu, fish with edible bones (anchovies {ikan bilis}, whitebait, fresh and canned sardines), calcium-fortified foods (milk, orange juice, water, breads, biscuits)
Phosphorus helps in
  • The body's use of calcium
  • Metabolism of carbohydrate and fat
  • Developing the structure of nucleic acid molecules important to the body
Phosphorus deficiency could result in
  • Painful joints
  • Fatigue
  • Numbness
  • Skin sensitivity
  • Changes in body weight
Phosphorus is available from

Legumes, nuts, cereals, dairy products.
Magnesium helps in
  • Metabolism in the cells
  • Strengthening of the bones along with calcium
  • Maintaining heart health
Magnesium deficiency, although rare, could result in
  • Rapid heartbeats
  • Fatigue
  • Irritability
  • Seizure
  • Insomnia
  • Poor memory
  • Depression
  • Hypertension
  • Confusion
Magnesium is available from

Cereal grains, legumes, nuts, green leafy vegetables, milk.
Iron helps in
  • Metabolism in the cells
  • Strengthening of the bones along with calcium
  • Maintaining heart health
Iron deficiency could result in
  • Anaemia
  • Fatigue
  • Paleness
  • Spoon-shaped nails
  • Dull eyes
Iron is available from

Iron-fortified baby cereals, red meats (beef, lamb), baked beans, liver, fish, poultry, shellfish, eggs, dried beans or lentils, spinach, enriched bread.
Zinc helps in
  • Metabolism of protein, carbohydrate and fat and alcohol
  • Protein synthesis, tissue growth and repair and wound healing
  • Taste acuity, hormone production and bone mineralisation
  • Blood clotting and cognitive functions
Zinc deficiency could result in
  • Anaemia
  • Delayed growth
  • Skeletal abnormalities
  • Delayed wound healing
  • Poor appetite
  • Glucose intolerance
  • Impaired sexual maturation
Zinc is available from

Meats (beef, pork, veal), fish, poultry, dark green vegetables, whole grains (wholemeal bread. brown rice).

Vitamins and minerals in combination
Some minerals and vitamins work together to support the body's growth. Other vitamins and minerals should be consumed along with different types of nutrients to help the overall growth of the body. Calcium, phosphorus and vitamin D, for example, work together to strengthen bones. Vitamin A requires fat to be absorbed. Vitamin C enhances iron absorbtion. That is why some kinds of foods should be eaten together and also why it is important for a meal to contain items from different food groups.

Singapore Recommended Daily Dietary Allowance (RDDA) For Iron & Calcium