Vitamins are essential micronutrients indispensable for the proper functioning of the body. They participate in metabolic processes, act in immune defense, energy production, tissue formation, and the body's biochemical balance. As the body cannot produce most vitamins in sufficient quantities, it is necessary to obtain them through diet.

Below, we present all known vitamins, grouped into water-soluble and fat-soluble, their functions, food sources, and diseases associated with their deficiency.

1. Fat-Soluble Vitamins

Vitamin A (Retinol, Beta-carotene)

Functions

• Essential for vision (rods and cones).

• Maintenance of skin and mucous membranes.

• Bone growth.

• Strengthening of the immune system.

Sources

• Liver, egg yolk, milk.

• Carrots, pumpkin, mango, spinach (rich in beta-carotene).

Deficiency

• Night blindness.

• Ocular xerosis (dryness).

• Increased risk of infections.

• Skin problems.

Vitamin D (Calciferol)

Functions

• Regulates calcium and phosphorus metabolism.

• Essential for bones and teeth.

• Acts on immunity and muscle function.

Sources

• Sun exposure (main).

• Fatty fish, eggs, fortified milk.

Deficiency

• Rickets (children).

• Osteomalacia / osteoporosis (adults).

• Muscle weakness and increased risk of infections.

Vitamin E (Tocopherol)

Functions

• Potent antioxidant.

• Protects cell membranes.

• Acts on immunity.

Sources

• Seeds, nuts, vegetable oils, avocado.

Deficiency

• Rare, but can cause muscle weakness.

• Neurological problems.

• Hemolytic anemia in newborns.

Vitamin K (Phylloquinone, Menaquinone)

Functions

• Essential for blood clotting.

• Participates in bone metabolism.

Sources

• Green vegetables (kale, broccoli, spinach).

• Liver.

• Partial production by intestinal bacteria.

Deficiency

• Hemorrhages and bleeding.

• Problems with bone calcification.

2. Water-Soluble Vitamins

Vitamin C (Ascorbic Acid)

Functions

• Antioxidant.

• Collagen production (skin, tendons, vessels).

• Increases iron absorption.

• Strengthens the immune system.

Sources

• Citrus fruits, guava, acerola, strawberries.

• Broccoli, bell peppers.

Deficiency

• Scurvy (bleeding gums, weakness, poor wound healing).

• Anemia.

• Decreased immunity.

B Complex

Below, each B vitamin separately:

Vitamin B1 (Thiamine)

Functions

• Carbohydrate metabolism.

• Proper nerve function.

Sources

• Meats, whole grains, seeds, beans.

Deficiency

• Beriberi (weakness, edema, heart problems).

• Wernicke-Korsakoff syndrome (common in chronic alcoholism).

Vitamin B2 (Riboflavin)

Functions

• Participates in energy production.

• Maintains healthy skin and eyes.

Sources

• Milk, eggs, meats, green vegetables.

Deficiency

• Cheilosis (cracks at the corners of the mouth).

• Dermatitis.

• Photosensitivity.

Vitamin B3 (Niacin)

Functions

• Energy metabolism.

• Skin and nervous system function.

Sources

• Meats, peanuts, fish, whole grains.

Deficiency

• Pellagra: dermatitis, diarrhea, dementia.

Vitamin B5 (Pantothenic Acid)

Functions

• Production of hormones and cholesterol.

• Energy metabolism.

Sources

• Almost all foods (meats, eggs, avocado).

Deficiency

• Rare; can cause fatigue, irritability, and tingling.

Vitamin B6 (Pyridoxine)

Functions

• Protein metabolism.

• Production of neurotransmitters (serotonin, dopamine).

• Hemoglobin formation.

Sources

• Meats, potatoes, bananas, seeds.

Deficiency

• Anemia.

• Depression and irritability.

• Seizures (severe cases).

Vitamin B7 (Biotin)

Functions

• Fat and carbohydrate metabolism.

• Health of skin, hair, and nails.

Sources

• Eggs, nuts, meats, cauliflower.

Deficiency

• Rare; can cause hair loss, dermatitis, and fatigue.

Vitamin B9 (Folic Acid)

Functions

• DNA and blood cell formation.

• Essential during pregnancy (baby's neural tube).

Sources

• Green vegetables, liver, beans, fortified cereals.

Deficiency

• Megaloblastic anemia.

• Fetal malformations (spina bifida).

• Fatigue and irritability.

Vitamin B12 (Cobalamin)

Functions

• Red blood cell formation.

• Neurological function.

• Cellular metabolism.

Sources

• Exclusively of animal origin: meats, milk, eggs.

Deficiency

• Pernicious anemia.

• Tingling and neurological damage.

• Memory loss.

Conclusion

Vitamins play vital roles in the body, and their absence can cause serious problems, ranging from anemia and decreased immunity to neurological damage and fetal malformations. A varied and balanced diet—rich in fruits, vegetables, grains, proteins, and healthy fats—is the best way to ensure adequate levels of all vitamins.

In specific cases, such as pregnant women, the elderly, vegans, or individuals with malabsorption conditions, supplementation may be necessary, always with professional guidance.

Vitamins are essential micronutrients indispensable for the proper functioning of the body. They participate in metabolic processes, act in immune defense, energy production, tissue formation, and the body's biochemical balance. As the body cannot produce most vitamins in sufficient quantities, it is necessary to obtain them through diet.

Below, we present all known vitamins, grouped into water-soluble and fat-soluble, their functions, food sources, and diseases associated with their deficiency.

1. Fat-Soluble Vitamins

Vitamin A (Retinol, Beta-carotene)

Functions

• Essential for vision (rods and cones).

• Maintenance of skin and mucous membranes.

• Bone growth.

• Strengthening of the immune system.

Sources

• Liver, egg yolk, milk.

• Carrots, pumpkin, mango, spinach (rich in beta-carotene).

Deficiency

• Night blindness.

• Ocular xerosis (dryness).

• Increased risk of infections.

• Skin problems.

Vitamin D (Calciferol)

Functions

• Regulates calcium and phosphorus metabolism.

• Essential for bones and teeth.

• Acts on immunity and muscle function.

Sources

• Sun exposure (main).

• Fatty fish, eggs, fortified milk.

Deficiency

• Rickets (children).

• Osteomalacia / osteoporosis (adults).

• Muscle weakness and increased risk of infections.

Vitamin E (Tocopherol)

Functions

• Potent antioxidant.

• Protects cell membranes.

• Acts on immunity.

Sources

• Seeds, nuts, vegetable oils, avocado.

Deficiency

• Rare, but can cause muscle weakness.

• Neurological problems.

• Hemolytic anemia in newborns.

Vitamin K (Phylloquinone, Menaquinone)

Functions

• Essential for blood clotting.

• Participates in bone metabolism.

Sources

• Green vegetables (kale, broccoli, spinach).

• Liver.

• Partial production by intestinal bacteria.

Deficiency

• Hemorrhages and bleeding.

• Problems with bone calcification.

2. Water-Soluble Vitamins

Vitamin C (Ascorbic Acid)

Functions

• Antioxidant.

• Collagen production (skin, tendons, vessels).

• Increases iron absorption.

• Strengthens the immune system.

Sources

• Citrus fruits, guava, acerola, strawberries.

• Broccoli, bell peppers.

Deficiency

• Scurvy (bleeding gums, weakness, poor wound healing).

• Anemia.

• Decreased immunity.

B Complex

Below, each B vitamin separately:

Vitamin B1 (Thiamine)

Functions

• Carbohydrate metabolism.

• Proper nerve function.

Sources

• Meats, whole grains, seeds, beans.

Deficiency

• Beriberi (weakness, edema, heart problems).

• Wernicke-Korsakoff syndrome (common in chronic alcoholism).

Vitamin B2 (Riboflavin)

Functions

• Participates in energy production.

• Maintains healthy skin and eyes.

Sources

• Milk, eggs, meats, green vegetables.

Deficiency

• Cheilosis (cracks at the corners of the mouth).

• Dermatitis.

• Photosensitivity.

Vitamin B3 (Niacin)

Functions

• Energy metabolism.

• Skin and nervous system function.

Sources

• Meats, peanuts, fish, whole grains.

Deficiency

• Pellagra: dermatitis, diarrhea, dementia.

Vitamin B5 (Pantothenic Acid)

Functions

• Production of hormones and cholesterol.

• Energy metabolism.

Sources

• Almost all foods (meats, eggs, avocado).

Deficiency

• Rare; can cause fatigue, irritability, and tingling.

Vitamin B6 (Pyridoxine)

Functions

• Protein metabolism.

• Production of neurotransmitters (serotonin, dopamine).

• Hemoglobin formation.

Sources

• Meats, potatoes, bananas, seeds.

Deficiency

• Anemia.

• Depression and irritability.

• Seizures (severe cases).

Vitamin B7 (Biotin)

Functions

• Fat and carbohydrate metabolism.

• Health of skin, hair, and nails.

Sources

• Eggs, nuts, meats, cauliflower.

Deficiency

• Rare; can cause hair loss, dermatitis, and fatigue.

Vitamin B9 (Folic Acid)

Functions

• DNA and blood cell formation.

• Essential during pregnancy (baby's neural tube).

Sources

• Green vegetables, liver, beans, fortified cereals.

Deficiency

• Megaloblastic anemia.

• Fetal malformations (spina bifida).

• Fatigue and irritability.

Vitamin B12 (Cobalamin)

Functions

• Red blood cell formation.

• Neurological function.

• Cellular metabolism.

Sources

• Exclusively of animal origin: meats, milk, eggs.

Deficiency

• Pernicious anemia.

• Tingling and neurological damage.

• Memory loss.

Conclusion

Vitamins play vital roles in the body, and their absence can cause serious problems, ranging from anemia and decreased immunity to neurological damage and fetal malformations. A varied and balanced diet—rich in fruits, vegetables, grains, proteins, and healthy fats—is the best way to ensure adequate levels of all vitamins.

In specific cases, such as pregnant women, the elderly, vegans, or individuals with malabsorption conditions, supplementation may be necessary, always with professional guidance.