Nutrients provide all of the necessary elements to promote our bodies growth and development and to regulate our bodies’ processes. so It a critical part of health and development.
Good nutrition is related to improved health, stronger immune systems, safer pregnancy and childbirth, lower risk of non-communicable diseases and longevity.
Healthy children learn better. People with adequate nutrition are more productive.
Nutrients can be divided into two categories: macronutrients, and micronutrients.
A. Macronutrients
The term macronutrient simply means that the nutrient is needed in large quantities for normal growth and development. Macronutrients are the body’s source of calories, or energy to fuel life processes.
Macronutrients include carbohydrate, protein, and fat.
1. Carbohydrates
- Carbohydrates include sugar, starches & fibres (fruits, grains & vegetables).
- Carbohydrates are easily broken down into glucose (directly used by brain & muscle) so it is the main source of Energy.
- Energy 4 calories/1g of carbohydrates
- Simple or bad carbohydrates generally release sugar faster (like refined table sugar) & do not contain any micronutrients like vitamins, minerals or fibres.
- While complex/good carbohydrates are available with various nutrients and good for health.
- Complex carbohydrates should be incorporated into diet
- Fruits
- Vegetable
- Whole wheat grains (Brown rich, whole wheat bread)
- Legumes such as lentils, Chickpeas
- Carbohydrates consumed in the diet are also stored as glucose in liver & muscles cells to provide a rapid source of energy by breakdown into glucose.
2. Protein
- Protein are made up of amino acids.
- It function as hormones, enzymes & Antibody (Immune system).
- Also make up parts of body structures like connective tissue, skin, hair & muscle fibres- Building Blocks of human structure).
- Protein do not serve as a direct source of energy like carbohydrates.
- Essential amino acids- Body can not synthesize them so must be supplied into diet.
- Recommended daily intake= 0.75-1 g/kt of body wt.
- Better source of proteins are Animals & Soy
- Other sources are
- Legumes
- Eggs
- Fish
- Nuts
- Seeds
- Meat
3. Fats
- There are two types of fats: Saturated & Unsaturated fat.
- Our body needs the unsaturated fat & since unsaturated fat regulate metabolism, maintains the elasticity of cell membrane, improve blood flow, promote cell growth & regeneration.
- Also fat helps in delivery of fat soluble vitamins (A,D,E & K) into the body.
- Cholesterol (saturated) fat is also synthesize by our body. It play important role in hormone production (Vitamin D, Sex steroid), building of cell membranes, bile acid production etc. However, a diet in rich cholesterol can increase the risk of heart diseases.
- Daily recommended intake= 30-35 % of your daily caloric intake.
- Fats to be include in our diet are-
- Avocados
- Fish
- Olive oil
- Dairy
- Nuts
- Eggs
- Chia seeds
- Essential Fatty acid (unsaturated fat) must be supplied in the diets since carbs & protein cannot produce them. Omega-3/Linolenic acid; Omega-6/Linoleic acid.
- Omega-3 reduce blood clotting, dilate blodd vessels, reduce inflammations, reduce cholesterol & TG levels.
- Also Omega-3 reduce the risk of mental illness & ADHD (attention deficit hyperactivity disorder).
B. Micronutrients
Micronutrients, are only needed in small amounts, (as per WHO) also called ‘magic wands’.
These enable the body to produce enzymes, hormones and other substances essential for proper growth and development”
Micronutrients are classified into two major classes i.e vitamins and minerals.
- Vitamins
- Minerals
- Water
| Vitamins | Minerals | Water |
|---|---|---|
| Water Soluble -Vitamin B1 -Vitamin B2 -Vitamin B6 -Vitamin B12 -Vitamin C -Folic Acid Fat Soluble -Vitamin A -Vitamin D -Vitamin E -Vitamin K | Calcium Potassium Sodium Iron Zinc | Water |
1. Vitamins
a. Water Soluble Vitamins
| Vitamin | Physiological role | Deficiency |
|---|---|---|
| Thiamin (B1) | Co-enzyme functions in metabolism of carbohydrates and branched-chain amino acids | Beri-beri, polyneuritis, and Wernicke-Korsakoff syndrome |
| Riboflavin (B2) | Co-enzyme functions in numerous oxidation and reduction reactions | Growth, cheilosis, angular stomatitis, and dermatitis |
| Niacin (nicotinic acid and nicotinamide) | Co-substrate/co-enzyme for hydrogen transfer with numerous dehydrogenases | Pellagra with diarrhoea, dermatitis, and dementia |
| Vitamin B6 (pyridoxine, pyridoxamine, and pyridoxal) | Co-enzyme functions in metabolism of amino acids, glycogen, and sphingoid bases | Naso-lateral seborrhoea, glossitis, and peripheral neuropathy (epileptiform convulsions in infants) |
| Pantothenic acid | Constituent of co-enzyme A and phosphopantetheine involved in fatty acid metabolism | Fatigue, sleep disturbances, impaired coordination, and nausea |
| Biotin | Co-enzyme functions in bicarbonate-dependent carboxylations | Fatigue, depression, nausea, dermatitis, and muscular pains |
| Vitamin | dietary sources |
|---|---|
| Thiamin (B1) | Pork, organ meats, whole grains, and legumes |
| Riboflavin (B2) | Milk and dairy products, meats, and green vegetables |
| Niacin (nicotinic acid and nicotinamide) | Liver, lean meats, grains, and legumes; can be formed from tryptophan |
| Vitamin B6 (pyridoxine, pyridoxamine, and pyridoxal) | Meats, vegetables, and whole-grain cereals |
| Pantothenic acid | Animal tissues, whole-grain cereals, and legumes; widely distributed |
| Biotin | Liver, yeast, egg, yolk, soy flour, and cereals |
Folate/folic acid & Vitamin 12
| Vitamin | Physiological role | Effects of Deficiency and Toxicity |
|---|---|---|
| Folate (folic acid) | Maturation of red blood cells, Synthesis of purines, pyrimidines, and methionine, Development of fetal nervous system | Deficiency: Megaloblastic anemia, neural tube birth defects, confusion |
| Vitamin B12 (cobalamins) | Maturation of red blood cells, neural function, DNA synthesis, myelin synthesis and repair | Deficiency: Megaloblastic anemia, neurologic deficits (confusion, paresthesias, ataxia) |
| Vitamin C (ascorbic acid) | Collagen formation, Bone and blood vessel health, Carnitine, hormone, and amino acid formation, Wound healing | Deficiency: Scurvy (hemorrhages, loose teeth, gingivitis, bone defects) |
| Nutrient | Principal Sources |
|---|---|
| Folate (folic acid) | Raw green leafy vegetables, fruits, organ meats (eg, liver), enriched cereals and breads |
| Vitamin B12 (cobalamins) | Meats (especially beef, pork, and organ meats [eg, liver]), poultry, eggs, fortified cereals, milk and milk products, clams, oysters, mackerel, salmon |
| Vitamin C (ascorbic acid) | Citrus fruits, tomatoes, potatoes, broccoli, strawberries, sweet peppers |
b. Fat Soluble vitamin
| Vitamin | Physiological role | Effects of Deficiency and Toxicity |
|---|---|---|
| Vitamin A (retinol) | Formation of rhodopsin (a photoreceptor pigment in the retina), Integrity of epithelia, Lysosome stability, Glycoprotein synthesis | Deficiency: Night blindness, perifollicular hyperkeratosis, xerophthalmia, keratomalacia, increased morbidity and mortality in young children Toxicity: Headache, peeling of skin, hepatosplenomegaly, bone thickening, intracranial hypertension, papilledema, hypercalcemia |
| Vitamin D (cholecalciferol, ergocalciferol) | Calcium and phosphate absorption, Mineralization and repair of bone, Tubular reabsorption of calcium, Insulin and thyroid function, improvement of immune function, reduced risk of autoimmune disease | Deficiency: Rickets (sometimes with tetany), osteomalacia Toxicity: Hypercalcemia, anorexia, renal failure, metastatic calcifications |
| Vitamin E group (alpha-tocopherol, other tocopherols) | Intracellular antioxidant, Scavenger of free radicals in biologic membranes | Deficiency: Red blood cell hemolysis, neurologic deficits Toxicity: Tendency to bleed |
| Vitamin K group (phylloquinone, menaquinones) | Formation of prothrombin, other coagulation factors, and bone proteins | Deficiency: Bleeding due to deficiency of prothrombin and other factors, osteopenia |
| Nutrient | Principal Sources |
|---|---|
| Vitamin A (retinol) | As preformed vitamin: fish liver oils, liver, egg yolks, butter, vitamin A–fortified dairy productsAs provitamin carotenoids: dark green and yellow vegetables, carrots, yellow and orange fruits |
| Vitamin D (cholecalciferol, ergocalciferol) | Direct ultraviolet B irradiation of the skin (main source), fortified dairy products (main dietary source), fish liver oils, fatty fish, liver |
| Vitamin E group (alpha-tocopherol, other tocopherols) | Vegetable oils, nuts |
| Vitamin K group (phylloquinone, menaquinones) | Green leafy vegetables (especially collards, spinach, and salad greens), soy beans, vegetable oilsBacteria in the gastrointestinal tract after neonatal period |