Minerals | Micro Nutrients

[1st Semester Nutrition | UNIT 4.1 BHM116 | IHM Notes]

Mineral elements are inorganic substances found in the body tissues and fluids. They comprise 4-6% of our body weight.

Two distinct characteristics are:

• They do not provide energy

• They are not destroyed during food preparation

Minerals are classified into 3 groups

1. Macro minerals/major (over 100 mg/D): calcium, phosphorus, sodium, chlorine

2. Minor minerals (less than 100mg/D): iron, manganese

3. Trace minerals (few mcg to mg/D): iodine, fluorine, zinc, molybdenum

Calcium

Functions:

• Structural component- required for the formation and maintenance of skeleton and teeth.

• For normal contraction of muscles like to make heartbeats

• Required for nervous activity

• Has a role in blood clotting.

Food sources:

• Rich amongst animal sources are milk and milk products like curd, paneer, buttermilk, skim milk powder

• Amongst plant foods Green leafy vegetables, fenugreek, drumstick

• Ragi is a rich source in cereal and millets and sesame seeds (til).

• Small fresh and dried fish

Deficiency:

• Severe deficiency will lead to fragility/weakness of bones. This leads to osteoporosis in adults and rickets in children which is the manifestation of Vit. D.

• Excessive intake leads to Tetany: symptoms are muscular pain and twitching of facial muscles.

RDA- 600mg/day

Iron

Functions:

• Essential element for the formation of Hb.

• An important role in the transport of oxygen

Food sources:

• Liver, organ meat are excellent sources as are readily available form

• Rich sources are cereals like whole wheat flour, rice flakes, millets like bajra, ragi, pulses, and GLVs

Vitamin C helps in iron absorption

Deficiency:

• Deficiency of Iron causes Iron Deficiency Anaemia.

• Symptoms are general fatigue, breathlessness on exertion giddiness and pallor of skin (paleness), spoon-shaped nails.

RDA: Male:17mg/day Female: 21 mg/day.

Sodium

Functions:

• Maintains fluid balance, osmotic balance between intracellular and extracellular compartments.

• Keeps cell in proper shape.

• Maintains normal irritability of nerves and helps in normal contraction.

• Regulates cell permeability or passage of substances into and out of the cells.

Food sources:

• GLVS, fruit, milk, meat, Bengal gram dhal

• Besides imparting taste to the food, salt provides a necessary amount of sodium required by the body.

Sodium is lost in the urine and particularly in sweat as NaCl.

Deficiency occurs in high physical activities. Also, in case of severe vomiting and diarrhoea.

It results in weakness, giddiness, nausea and muscle cramps.

Excessive intake leads to hypertension.

For a healthy person, the minimum requirement is 500mg. maximum intake should not exceed 5 grams.

Iodine

• Most of the iodine in the adult body is found in the thyroxine gland.

• A major function is that iodine is a constituent of thyroxine.

• It regulates the rate of oxidation within the cells.

Food Sources:

• Seafood contains max iodine

• Salt is also iodized to overcome the epidemic of iodine deficiency

Deficiency:

Iodine deficiency causes Goitre.

• It is characterized by swelling of the thyroid gland in the neck.

• Its deficiency during fatal stage may lead to mental retardation in later life and retardation of body growth.

• This together is called as IDD: Iodine Deficiency Disorder

• Deficiency is seen in areas where the soil is deficient in iodine and water also.

• Besides these certain compounds present in foods, particularly vegetables of brassica species interfere with iodine utilization and leads to goitre.

The daily requirement is 100-150μg.

Fluorine

Required for development of normal bones and teeth.

Food Sources:

• Rich sources are sea fish, milk, cheese, tea

• Water is the main source of fluorine

Deficiency:

The deficiency of fluorine causes dental caries where drinking water contains less than 0.5 ppm of fluorine thus fluorination is done.

Excessive intake leads to a condition called Fluorosis.

Symptoms are:

Dental fluorosis:

• teeth lose their shine and chalky white patches appear on teeth it is called Mottling of teeth.

• later white patches become yellow.

• in severe cases, the enamel of teeth gets eroded leading to depression on the teeth surface, known as Pitting.

Skeletal fluorosis:

• In older adults, fluorosis leads to changes in bones.

• Initially pain in neck and stiffness of the back.

• At later stages, the person becomes bedridden.