B VITAMINS

B Vitamins are a group of water-soluble vitamins that are important for cell metabolism. There are 8 main vitamins present in this group. These include Vitamins B1, B2, B3, B5, B6, B7, B9 and B12. Mostly, all these vitamins are present in same foods. The combination of all these vitamins in a supplement is known as Vitamin B Complex. Whole grains are the best source of these vitamins except for vitamin B12 which is only present in animal foods.

Vitamin B1

Vitamin B1 or thiamine is especially important for the final metabolism of carbohydrates and few amino acids. Its deficiency causes the disease beriberi.

Central Nervous System (CNS) depends almost entirely on carbohydrates metabolism for its energy. Beriberi reduces the utilization of carbohydrates more than 50% to nervous system that can cause swelling of brain, emotional disturbances and irreversible loss of memory. Beriberi also weakens heart that produces irregular heartbeat and even heart failure in severe deficiency. The last major effect of beriberi is on GIT. Due to failure of getting enough energy from carbohydrates by the smooth muscles and glands of GIT, the problems of severe constipation, indigestion, anorexia etc. can produce.

Rich dietary sources of vitamin B1 are whole grains, sunflower seeds, cauliflower, oranges, potato, liver and eggs.

Recommended Daily Allowance (RDA) FOR Vitamin B1 is 1.4 mg. There’s no known toxicity from oral intake and therefore there’s no tolerable Upper Limit (UL) for this vitamin. 

Vitamin B2

Vitamin B2 or riboflavin is also important for several metabolic functions. Its deficiency produces symptoms like burning sensation of skin & eyes, digestive problems, cracks in the lips & corner of mouth, mental depression, headaches etc.

Good sources of vitamin B2 are milk, cheese, yogurt, leafy vegetables, liver, whole grains, almonds etc. RDA is 1.2 mg for adults while there’s no UL due to absence of toxic effects from dietary sources. 

Vitamin B3

Vitamin B3 or niacin plays an important role in the metabolism of glucose and fat. Its deficiency produces pellagra. Its symptoms include inflammation of skin, muscle weakness, insomnia, diarrhea, gastrointestinal hemorrhage, mental confusion, psychoses and permanent dementia.

Rich dietary sources are whole grains, legumes, chicken breast, beef, fish, dates, tomatoes etc. RDA is 16mg for men and 14 mg for women. UL is 35 mg/day. 

Vitamin B5

Vitamin B5 or Pantothenic Acid is important for the synthesis of Coenzyme A (CoA) while this coenzyme plays important function in the synthesis of antibodies, amino acids, cholesterol, fatty acids, steroid hormones, phospholipids etc.

Small amount of vitamin B5 can be produced in the body and also it is available in almost all foods. Due to these reasons, its deficiency is rare. Deficiency symptoms are acne and other skin problems.

Rich sources of this vitamin are whole grains, meat, eggs, royal jelly and yogurt. RDA is 5 mg for adult male and female. There’s no UL of vitamin B5 as no toxic effects have been seen so far. 

Vitamin B6

Vitamin B6 or Pyridoxine is important for the metabolism of amino acids, hemoglobin and lipids. Deficiency symptoms are microcytic anemia (decrease size of RBCs), high blood pressure, water retention, depression, skin inflammation etc.

Rich sources of vitamin B6 include fish, chicken, liver, soybeans, bananas, raisins, cauliflower, potatoes, blackstrap molasses etc.

RDA is 1.3 mg. UL is 100 mg/day. 

Vitamin B7

Vitamin B7 or Biotin is important for the metabolism of carbohydrates, lipids and protein. Deficiency can produce hair loss, inflammation of eye and skin. It can also cause neurological disorders and growth problems in children. Rich sources are green leafy vegetables, egg yolk (raw) and liver. 

Vitamin B9

Vitamin B9 or folic acid is needed for the formation of DNA. The two most important functions of folic acid are the promotion of growth and maturation of red blood cells. Its deficiency causes macrocytic anemia (large size of RBCs due to failure of their division). Other major deficiency symptoms include confusion, depression, diarrhea, low fertility in both men & women and pregnancy problems in women. People who consume alcohol are in danger of folic acid’s severe deficiency.

Main dietary sources of vitamin B9 include green leafy vegetables (especially spinach), fruits, nuts, grains and animal foods (especially liver).

RDA for adult is 400 micrograms while UL for people 19 and above is 1000 micrograms/day. Its toxicity can produce permanent damage to nervous system.

Vitamin B12

Vitamin B12 or cobalamin is slightly different from other B vitamins due to two reasons. First, it is only present in animal foods and secondly though it is a water-soluble vitamin like other B vitamins, it can be stored in liver in a bound form for a year if taken in higher amounts.

Vitamin B12 is important for metabolism of proteins, lipids & carbohydrates and for the production & maturation of red blood cells. It also acts as growth promoter.

Its deficiency produces macrocytic anemia, memory loss and psychosis. Absorption through gut decreases with age and elderly people are most likely to suffer from vitamin B12 deficiency.

Its food sources include fish, liver, meat, poultry, milk etc. RDA for adults is 2 micrograms/day while there’s no UL (upper limit) due to absence of toxic value. 

VITAMIN C

Vitamin C or ascorbic acid is a water-soluble vitamin. Thus, it can not be stored in the body and a certain amount of vitamin C is required daily to accomplish various body functions. The most important function of vitamin C is the formation of collagen fibers, present in subcutaneous tissue (hypodermis), cartilage, teeth and bone. It also acts as an antioxidant. 

Functions of vitamin C

·         Due to the antioxidant properties of vitamin C, it may have positive effects against certain diseases caused by oxidative stress including hypertension, diabetes, cardiovascular diseases, inflammatory diseases etc. Though, its positive effects are not quite evident in clinical studies so far.

·         Vitamin C is important for immune system. During infections, it is used quickly by the body. It is believed to be useful for white blood cells like monocytes, phagocytes and lymphocytes.  

·         Vitamin C also has antibiotic properties. A research in 2013 has proved that this vitamin can kill dug-resistant bacterium of tuberculosis.

·         Vitamin C is also important for absorption of iron from GIT.

·         Vitamin C can reduce the duration of common cold.

Deficiency Symptoms

Severe deficiency of vitamin C causes a disease named scurvy. It is due to the defect and weakness of collagen fibers, as stated above.

·         The most important effect of scurvy is the failure of wounds to heal. With vitamin C deficiency, wounds may take several months to heal instead of normal few days.

·         This disease also negatively affects bone growth. The growing bones can fracture easily at the growth point. Also in adults, the already fractured bone will not heal in case of vitamin C deficiency (scurvy).

·         Scurvy also causes the fragility of blood vessel walls. It causes the rupture of capillaries and the result is hemorrhages throughout the body.

·         Extreme scurvy will produce infection of mouth, loosening of teeth, bloody stools, blood-vomiting and death.

Dietary Sources of Vitamin C

Citrus Fruits are good source of Vitamin C

Vitamin C is mostly present in fresh fruits and raw vegetables. Their main dietary sources include: (per 100g amount).

Rose hip (426 mg), Green Chili Pepper (244 mg), Guava (228 mg), Red Chili Pepper (144 mg), Papaya (60 mg), Strawberry (60 mg), Orange (53 mg), Lemon (53 mg), Pineapple (48 mg), Cauliflower uncooked (48 mg), Grapefruit (30 mg), Mango (28 mg), Red Tomato (13.7 mg) and others.

These values are according to USDA.

Vitamin C is the most sensitive vitamin. It is highly affected by cooking, heat, air and light. 

RDA & UL

Recommended Daily Allowance (RDA) of vitamin C is 90 mg/day for adult male and 75 mg/day for adult female. Tolerable Upper Level (UL) for both adult male and female is 2000 mg/day. RDA is slightly higher than minimum requirement.

Overdose

Vitamin C can cause various problems if taken in amounts more than their upper limits. These include headache, fatigue, vomiting, diarrhea, disturbed sleep while it can cause skin rashes in infants. 

VITAMIN K

Vitamin K is a fat-soluble vitamin. This vitamin is very important for blood clotting and bone strength. Naturally, it has two main parts: vitamin K1 and vitamin K2. Vitamin K1 is abundant in vegetables especially green leafy vegetables while vitamin K2 is present in animal foods while it is also synthesized by bacteria in colon including conversion of vitamin K1to K2. 

Functions of Vitamin K

Vitamin K1 or Phylloquinone is very important for blood-clotting because of its main function in the production of coagulation factors II, VII, IX & X in liver. In its deficiency or absence, lot of blood can be lost from body after an injury due to weakness or failure of blood-clotting function.

Vitamin K2 or menaquinones is very important for bone density and strength. Its deficiency can cause different bones to be easily fractured due to fragility. 

Presence in Foods

Different green leafy vegetables including kale, spinach, turnip, cabbage etc. are rich in vitamin K1. The presence of this vitamin increases many folds when these vegetables are cooked.

Vitamin K2 is abundant in animal foods especially egg yolk, butter, chicken liver, cheddar cheese, chicken meat etc. 

Bacteria in colon can also synthesize vitamin K2 from vitamin K1. Using antibiotics in large amounts can destroy colon bacteria that can cause vitamin K2 deficiency.

RDI & UL

Recommended Daily Intake of Vitamin K is 120 micrograms/day for adult male and 90 micrograms/day for adult female.

There is no toxicity proved for naturally acquired vitamin K1 and K2. Therefore, there is no upper tolerable limit for vitamin K taken through diet. 

VITAMIN E

Vitamin E is a fat-soluble vitamin present in many plant foods. It is an antioxidant and its main function is to prevent the oxidation of unsaturated fatty acids. Its absence causes abnormal functions and structures of mitochondria, cell membrane etc.

It has been proved in experiments on lower animals that deficiency of vitamin E can cause sterility in male and female. The deficiency causes degeneration of germinal epithelium in the testes of males while its lack is also responsible for resorption of fetus in females. Its “anti-sterility” function in humans is not known exactly.

Its deficiency also affects the performance of muscle cells and renal tubular cells.

Deficiency Symptoms

Few important symptoms of vitamin E deficiency include:

·         Myopathy (muscle weakness that leads to muscle cramp and spasm).

·         Skeletal Myopathy (weakness of bones).

·         Retinopathy (damage to retina of eye).

·         Ataxia (lack of coordination of muscle movements).

·         Peripheral Neuropathy (disease of nerves leads to impair function of organ, gland, sensation or movement).

RDI & Dietary Sources

Recommended Daily Intake of vitamin E for people of age 14 and above is 15mg/day. The RDI reduces with lesser age.

Vitamin E is especially present in plants oil. Rich sources are wheat germ oil (150mg/100g), sunflower oil, safflower oil, olive oil, nuts & nuts oils like almonds and hazel nuts. Good sources are green, leafy vegetables including spinach, turnip, beet greens etc. while moderate amount of vitamin E is present in sesame oil, pumpkin, mangoes, tomatoes, papaya, lettuce etc. It is also present in few animal foods such as butter. 

Excess of Vitamin E

The tolerable upper limit (UL) of vitamin E is 1000mg/day. Overdose of vitamin E is called Hypervitaminosis E, responsible for deficiency of Vitamin K that can lead to bleeding problems. Overdose of vitamin E can be life-threatening if it combines with drugs like aspirin. 

VITAMIN D

Vitamin D is a fat-soluble vitamin, needed by the body especially for bone health. Vitamin D3 (cholecalciferol) is the most important form of vitamin D for human body. Vitamin D is very important for absorption of calcium and phosphorus from intestines, along with reduction of calcium and phosphorus excretion from kidneys. Through these actions, vitamin D enhances the mineralization of bones. 

Importance of Vitamin D

As mentioned above, vitamin D is very important for mineralization and strength of bones. Its deficiency, especially in children and aged people, can cause skeletal weakness and many other bone diseases.

Vitamin D supplementation can reduce the risk of several heart diseases including cardial infarction, stroke etc by about 15%.

Vitamin D is also important for immune system. Its deficiency can increase the risk of viral diseases (influenza, HIV etc) and tuberculosis.

Vitamin D also has moderate positive effects on patients with depression. 

Deficiency of Vitamin D

Deficiency of Vitamin D is the reason of major skeletal health problems. Its deficiency leads to rickets, osteomalacia and osteoporosis. All these diseases are mainly due to impaired bone mineralization.

Rickets is the disease of children. Its symptoms include tenderness of bones, weakness of muscles, teeth problems, growth disturbance, bones fractures, tetany (uncontrolled muscle spasms) etc.

Osteomalacia is the disease of adults and its reason and symptoms are quite similar to rickets. It is also called ‘rickets of adults’. Both rickets and osteomalacia can be treated by administration of adequate vitamin D.
  

Osteoporosis is the disease of women after menopause and aged men. It has no particular symptom but it reduces the strength of bones and they can easily be fractured or broken. The bones of wrist, rib, hip and vertebral column are most susceptible for fractures in osteoporosis. Its treatment is different and more complex than other bone diseases as apart from administration of calcium and vitamin D, other medications are also required for treatment. 

Daily Requirement

RDA for vitamin D is 15 microgram/day for people aged 1 to 70 years. People older than 70 years need 20 microgram/day of vitamin D.

Tolerable upper intake for 9 years and older is 100 microgram/day (4000 IU/day). 

Sources of Vitamin D

Vitamin D3 can be acquired from dietary sources and ultraviolet rays of sun. In natural dietary sources, it is only present in animal fats. It is abundant in fish oils and fatty fish species especially cod liver oil, catfish, salmon, sardines, tuna etc. Moderate amounts are also present in egg yolk and beef liver. Amount of Vitamin D  in milk can be increased by placing it under UV rays of sun.

Another important source of vitamin D3 is the ultraviolet B rays of sun. Whole-body exposure in sunlight can produce 10,000 IU (250 microgram) or more vitamin D3 in about half hour. The excess of vitamin D produces through UV rays on skin has no negative effects on body. UV rays of sunlight produces vitamin D from cholesterol beneath the skin. 

Excess of Vitamin D

Like Vitamin A, vitamin D also produces negative effects in body if taken in amount higher than upper tolerable intake. It is called hypervitaminosis D and its symptoms include decreased appetite, dehydration, irritability, vomiting, constipation, muscle weakness etc. This condition can be reversed by combining low calcium diet with corticosteroid drugs. 

VITAMIN A

Vitamin A or retinol is a fat-soluble vitamin. It is very important for vision, immune system, skin and growth. It is only present in animal fats while few carotenes in plant foods (especially beta-carotene) act as pro-vitamin A and some part of these carotenes can be converted into Vitamin A by lever. 

Importance for Health

Vitamin A is especially important for vision. It is needed by retina to form retinal pigments which prevents night blindness. Retina of eye is necessary for both colour vision and low light.

It is also important for skin as it reduces dryness of skin by the growth of mucus-secreting cells and also down-regulate production of sebum. It can also treat and reverse skin problems like photodamage (sun-damaged skin), cellulite and striae (stretch marks).

Vitamin A is also important for immune system. It is helpful in maintaining immune systems including macrophages, neutrophils, lymphocytes etc.

Vitamin A is beneficial for human growth hormone which is important for growth of body cells.

It is also necessary for production of blood cells.

Deficiency Symptoms

·         Night blindness is the earliest sign of Vitamin A deficiency. Persistent and severe deficiency produces xerophthalmia (eye dryness) due to atrophy of mucus-secreting cells which can lead to total blindness.

·         Lack of immunity can lead to ear infection, urinary tract infection and several other infections.

·         Dryness of skin and acne.

·         Impairment of growth of body cells including skeletal growth.

·         Enamel hypoplasia (thinning and deficiency of teeth enamel).

·         Reproductive problems in both males and females. In males, it is due to atrophy of testes germinal epithelium while due to interruption of sexual cycle in females. 

Daily Requirement

The daily requirement of Vitamin A differs with age, sex and other factors. RDA (recommended daily intake) for men between 19 and 70 years of age is 900 micro-grams while for the women of same age is 700 micro-grams. Upper limit for both male and female is 3000 micro-grams. RDA is slightly higher than minimum requirement. 

Food Sources

Carrots are main plant source of Vitamin A

Vitamin A is directly present in animal foods and indirectly in plant foods (as pro-vitamin A carotenes). Foods with higher amount are given below. It is given as their quantity per 100 grams and percentage according to RDA of men.

·         Liver (beef, fish) > (6500 micro-grams, 722%)

·         Liver (chicken) > (3296 micro-grams, 366%)

·         Carrot > (835 micro-grams, 93%)

·         Sweet Potato (raw) > (709 micro-grams, 89%)

·         Butter > (684 micro-grams, 76%)

·         Spinach > (469 micro-grams, 52%)

·         Pumpkin > (400 micro-grams, 41%)

·         Cheddar Cheese > (256 micro-grams, 29%)

·         Egg > (140 micro-grams, 16%)

·         Apricot > (96 micro-grams, 11%)

These values are according to USDA. 

Problems with Higher Intake

Vitamin A can be dangerous if taken in amount greater than tolerable upper limit (3000 micro-grams for most men and women). The condition is known as Hypervitaminosis A. Its symptoms include softening of skull bone, blurred vision, decreased appetite, headache, drowsiness, nausea, hair loss etc.

This condition can be treated by avoiding high intake of Vitamin A. 

VITAMINS

A vitamin is a micro-nutrient needed in smaller amounts through diet to keep the body healthy. There are two main types of vitamins according to their solubility. These are fat-soluble vitamins and water-soluble vitamins.

Fat Soluble vitamins mostly present in fatty foods and are soluble in fat also. These include Vitamin A, Vitamin D, Vitamin E and Vitamin K. As fats can be stored in body so these vitamins can also be stored in body if taken in amounts greater than necessary. Vitamin A can be stored in the liver for more than 5 months while Vitamin D storage in liver is sufficient for over 2 months. Some of them, especially vitamins A and D are very dangerous if taken in amounts greater than their upper limits.

Water Soluble vitamins are present and soluble in water. These are B vitamins and vitamin C. Due to their solubility in water, they can’t be stored in body in larger amounts. Therefore, these vitamins should be part of our daily diet in sufficient amount. Symptoms in Vitamin C deficiency can appear after few weeks while Vitamin Bs deficiency symptoms can occur after just few days. Vitamin B12 is an exception as it can be stored in liver for about 1 year in bound form although it is a water-soluble vitamin. 

Cooking Effects

Cooking of food effects loss of several vitamins in different percentages. The loss of vitamins B1, B3, B5, B9 and C is greater than 15% while the loss of vitamins A and E is about 10%. Cooking can also be beneficial for vitamins as it allows more vitamins to be absorbed by those foods which are otherwise difficult to absorb due to the hard structure of food. 

Exposure Effects

The exposure of foods to air, light and heat can also reduce vitamins in these foods from high degree to low levels.

Vitamins C and E are much affected by their exposure to air.

Exposure to light significantly reduces quantities of vitamins C, E, K, B6 and B12.

The percentage of vitamins C and B5 are greatly reduced by their exposure to heat while at high temperatures, vitamins B1 and B9 also reduce markedly.

Vitamin A is little affected by exposure to all these factors while their effect on certain vitamins is not properly known so far. 

Supplementation & Fortification

Apart of their natural presence in foods, these vitamins can also be obtained by vitamin supplements and fortification of certain foods.

Multivitamin supplements are available in the form of tablets, capsules, powders etc while certain foods are fortified or enriched with micro-nutrients including vitamins. These supplements and fortified foods can compensate the deficiency of vitamins and minerals in various groups of people especially old age people but their absorption in the body is limited and also their high doses can be harmful for body. Therefore, it is recommended to use natural foods to attain vitamins as much as possible while supplements and fortified foods should only be consumed when getting adequate vitamins from natural source is not possible. 

PROTEIN

Protein is a macro-nutrient required mainly for growth and repair functions of body. They also provide energy when stores of carbohydrates and fats are diminished. They produce 4 calories per gram which is equal to that of carbohydrates and half that of fats. Proteins are made up of amino acids. There are 20 amino acids present in human body out of which about half are essential amino acids. These essential amino acids should be taken from diet as the body cannot produce them by itself. 

Sources of Protein

Proteins are present in both animal and plant foods. They are abundant in meat, eggs, milk, fish, cereals, pulses, nuts etc. Animal proteins are better than plant proteins as all the essential amino acids are present in animal proteins in appropriate amount while plant proteins usually lack one or more amino acids. E.g. cereals lack the essential amino acid lysine while pulses are deficient in another essential amino acid methionine. The combination of both cereals and pulses can be a good trick for vegetarians but even than they’re not as good source of protein as animal proteins due to difference in quantity of different amino acids while they’re present in appropriate amount in animal protein. Therefore, a diet should constitute some animal proteins to remain healthy. 

Importance of Protein

·         Proteins are major constituents of muscles, bones, skin, hair, blood cells, immune system, many hormones, enzymes etc.

·         Proteins are the second most abundant kind of molecules in the body after water.

·         A healthy male between 19-70 years of age requires 56 grams of protein per day for remaining healthy while women of same age needs 46 grams of protein per day.

Protein during Exercise

The normal value for protein required by the body is 0.8 g/kg body weight. During exercise, this normal amount should be increased to repair the damage caused by hard exercise. Normal Aerobic exercise or endurance training don’t cause much wear and tear to body muscles but if they’re exercised for prolonged  time than it is  required to repair muscle break down by consuming extra amount of proteins in their diet. They should consume protein a maximum of 1.4 g/kg body weight.

On the other side, Anaerobic exercise or strength training cause much wear and tear to body muscles and large quantity of proteins are required along with anaerobic exercise to repair damaged muscle cells. The strength trainers should consume a maximum protein of 1.8 g/kg body weight to repair amino acid loss and enhance the synthesis of muscle protein. Doing strength training without taking extra amount of good proteins can be very harmful for body. 

Protein Deficiency

Severe protein deficiency can cause general learning disability and kwashiorkor (especially in children). The symptoms of kwashiorkor include fatty liver, diarrhea, apathy, swelling of belly, flaky skin etc. proteins are required by many parts and systems of body as mentioned above, so performance of all these organs and systems decreases with decrease in protein intake or consuming low quality protein (vegetarians who consume no animal foods).

Hormones effects on Protein Metabolism

Many hormones increase the retention of proteins (anabolism) in the body. These include growth hormone, insulin, testosterone and estrogen while few cause their breakdown (catabolism). Cortisol is most important among them. 

FATS & OILS

Fats & oils are macro-nutrients needed by human body to produce energy and perform different body functions. Fats are solid at room temperature while oils are liquid at room temperature. They both are collectively called lipids. Lipids mostly include triglycerides (neutral fat), phospholipids and cholesterol.

Triglycerides are used to provide energy to the body while phospholipids and cholesterol are used to form membranes of all body cells and also to perform other functions of cells. Cholesterol are also precursors to many hormones.

There are three main types of fats present in the food. These are: saturated fat, unsaturated fat and Trans fat. Saturated and unsaturated fats are naturally present in different foods while trans fats are made by hydrogenation of vegetable oils. 

Storage of Fats

Additional triglycerides are stored in the adipose or fat tissues of body. They remain inside the adipose tissue in liquid form and can be easily transported to blood when required. These cells also help to heat insulate the body during cold. 

Importance of Fats

·       Fats provide 9 calories/gram energy which is more than double to carbohydrates (4 calories/gram).

·         Cholesterol are precursors to many hormones including testosterone, estrogen, cortisol etc.

·         Vitamin A, Vitamin D, Vitamin E and Vitamin K are fat-soluble vitamins and they can only be digested, stored and transported through fats.

·         Fats promote healthy cell function, insulate body organs and maintain normal body temperature during cold weather.

·         Fats promote sebum production and thus maintain healthy skin and hair growth.

·         Fats protect vital organs like kidneys against physical shock etc.

Precautionary Measures

High intake of fats especially saturated and trans fats are very injurious for health. They can cause obesity, high blood pressure, atherosclerosis (development of plaque on arterial walls) and also few types of cancer including colon cancer. Therefore, their quantity in the food should be minimized to low levels. Oils should be given preference over fats as they’re easily digestible and transportable in the body. 

Presence in Foods

Most of the foods contain both saturated and unsaturated fats but saturated fats are more abundant in animal foods including cream, butter, egg yolk, fatty meat etc and few vegetable foods including coconut oil, palm kernel oil, cottonseed oil etc. Unsaturated fats are present mostly in plant foods e.g. canola oil, soybean oil, olive oil, sunflower oil, corn oil etc and also in few animal foods especially oily fish. 

Essential Fatty Acids

There are two types of unsaturated fats: monounsaturated and polyunsaturated fats. Omega-3 fatty acids and Omega-6 fatty acids are two essential fatty acids that should be taken by every individual in the food to remain healthy. These two essential fatty acids are present in oily fish, canola oil, pumpkin seeds, sunflower oil, walnuts etc.