Vitamins and minerals

Vitamins are a group of organic compounds your body requires for cell growth and development.

They play an essential role in ensuring that your body functions optimally. Vitamins are present in foods, fruits, and vegetables in not-so-large amounts. Everyone needs specific vitamins and other nutrients to live a healthy life. Unfortunately, lack of knowledge is one of the primary reasons you can miss out on these essential nutrients.

Groups of vitamins

There are thirteen essential vitamins that your body needs to function. These vitamins belong to two main groups based on how they act in your body.

• Fat-soluble vitamins: These are absorbed and stored in your body, particularly in your fatty tissues and liver. The four fat-soluble vitamins are vitamins A, D, E, and K. Your body stores an excess of these vitamins. You won’t need a daily supply of these vitamins in your diet. However, storing enough amounts equivalent to the daily recommended amount would be best.
• Water-soluble vitamins: As the name connotes, they are soluble in water. Unlike the fat-soluble vitamins, the body does not store water-soluble vitamins. It excretes excess amounts via urine. So, you need to include them in your diet to get the daily recommended supply. The nine water-soluble vitamins are vitamin C and B vitamins – B1, B2, B3, B5, B6, B7, B9 and B12.

This article will share more details on these vitamins, including their functions, food sources, signs of deficiency, and the dangers of overconsumption.

Vitamin A

Vitamin A is a fat-soluble vitamin that is naturally present in many foods. It exists in two primary forms:

• Preformed vitamin A: This is an active form of vitamin A, also known as retinol. This is found in animal products such as meat, fish, eggs, and dairy products.
• Provitamin A carotenoids: Carotenoids are naturally occurring pigments responsible for the yellow, red, and orange colours in plants, especially fruits and vegetables. The body converts these precursors into vitamin A. The most common provitamin A carotenoid is alpha-carotene and beta-carotene.

Functions of vitamin A

• Vision development
• Boosts immune function
• Development of healthy skin, teeth, skeletal and soft tissue, and mucous membrane
• Supporting proper growth and development

Body requirements and absorption:

The recommended daily allowances (RDAs) of vitamin A vary by age and gender. Males 14 years old and older should take 900 micrograms (mcg). Women 14 years and older should take 700 micrograms (mcg).

Factors that aid the absorption of vitamins include:

• Dietary absorption: Foods rich in vitamin A will be absorbed better when consumed with foods containing healthy fats.
• Gut health: Having a healthy gut microbiome
• Zinc: Including adequate amounts of zinc in your diet helps your body to process and absorb vitamin A better.

Natural Sources:

Palm oil, carrots, beef liver, eggs, sweet potatoes, leafy vegetables like spinach and pumpkin leaves (ugu) are natural sources of vitamin A.

Signs of Vitamin A deficiency:

• Xerophthalma or dry eye syndrome – severe dryness of the cornea and conjunctiva. As a result, the eye is unable to produce tears. If not treated, it can cause keratomalacia.
• Keratomalacia – an eye condition where the conjunctiva gets cloudy, and the cornea softens. If not treated, it can lead to blindness
• Night blindness or nyctalopia
• Hyperkeratosis – dry, scaly skin
• Low immunity, which leads to infections

 Dangers of overconsumption:

• Acute and chronic toxicity characterized by nausea, dizziness, hair loss, and itchy skin
• High doses of vitamin A, especially isotretinoin, can cause congenital disabilities during pregnancy
• Organ damage, especially to your heart and liver
• Skeletal abnormalities such as bone and joint pain, osteoporosis, and poor bone formation
• Anaemia

Vitamin B Complex

B complex vitamins are a group of essential nutrients comprising eight vitamins. These include vitamins B1, B2, B3, B5, B6, B9 and B12. They are all water-soluble vitamins. They work together to help you stay healthy.

Vitamin B1

Vitamin B1, known as thiamine, is a water-soluble vitamin. It dissolves in water and gets flushed out regularly. The body cannot store Vitamin B1, so you need it in your diet every day – luckily, you should be able to get all you need from there. This vitamin is essential during pregnancy and breastfeeding.

Functions

• Metabolism of carbohydrates to supply your body with energy
• Production of enzymes to break down blood sugar
• Normal growth and functioning of your nerve cells, central nervous system, and heart

Body requirements and absorption:

Adults need 0.8 to 1.1 milligrams (mg) of thiamine daily. It is absorbed readily in the jejunum and ileum of your small intestine.

Natural sources:

Potatoes, brown rice, eggs, beans, lentils, and nuts are excellent sources of vitamin B1.

Signs of deficiency:

Fatigue and muscle weakness are common signs of thiamin deficiency. It can also lead to a neurological disease called beriberi. Beriberi causes muscle loss, numbness from nerve damage, and impaired reflex and motor function.

Dangers of overconsumption:

Overconsumption of thiamine is unlikely because your body will excrete the excess amounts through your urine.

Vitamin B2

Vitamin B2 is known as ‘the skin saviour’ because it maintains healthy skin, nails and hair. It is also known as riboflavin.

Functions

• Growth and development of body cells
• Carbohydrates, proteins, and drug metabolism
• Maintaining healthy mucous membranes in your nose and mouth
• Collagen production in your skin, hair, and nails
• Boosts eye health
• Production of antibodies

Body requirements and absorption

The recommended daily allowance (RDA) of riboflavin is about 1.3 mg of vitamin B2. Women usually need 1.4mg daily during pregnancy. It is absorbed in the epithelial cells of the small intestine.

Natural sources

Ugu (pumpkin leaves), milk, cheese, yoghurt, meat, and eggs are excellent sources of riboflavin.

Signs of deficiency

• Cracked skin and lips
• Brittle hair and nails
• Sores and inflammation at the corners of the mouth and tongue
• Skin problem

Dangers of Overconsumption

Vitamin B2 is generally safe, but your urine may appear yellow.

Vitamin B3

It is also known as niacin and exists in different forms. It exists in your food as:

• Nicotinic acid
• Nicotinamide

Your body can also produce vitamin B3 from an amino acid called tryptophan. Consuming foods that are rich in protein will cause an increase in the tryptophan-nicotinamide conversion.

Functions

• DNA (deoxyribonucleic acid) repair
• Nutrient and energy metabolism
• Normal growth and functioning of cells
• Maintaining skin, brain, and digestive health
• Promote healthy cholesterol levels

Body requirements and absorption

Adults need an average of 15 mg of niacin daily. Nicotinamide and nicotinic acid are absorbed in the small intestine.

Natural sources

Meat, fish, brown rice, peanuts and coffee are rich in vitamin B3.

Signs of deficiency

Vitamin B3 deficiency can cause pellagra. This condition is a combination of dermatitis, dementia, and diarrhoea characterized by:

• Gastrointestinal complications – poor appetite, nausea, abdominal pain
• Brown discolourations and scaly lesions on your skin
• Lethargy, anxiety and depression

Dangers of overconsumption:

Taking too much niacin can cause bloating, nausea, diarrhoea and liver damage.

 Vitamin B5

Vitamin B5 is often called an ‘anti-stress vitamin.’ Your body requires this vitamin to make coenzyme A (CoA). CoA is responsible for several processes in your body, especially breaking down food to produce energy. Vitamin B5 is also known as pantothenic acid.

Functions

• Fat, protein, and carbohydrate metabolism for energy
• Boosts your immunity
• Aids digestion
• Production of sex and stress hormone
• Maintaining healthy skin and hair

Body requirements and absorption:

Your body can’t produce pantothenic acid. You need a daily intake of 5mg from your diet if you are older than 14 years. The presence of gastric acid in your stomach aids vitamin B5 absorption.

Natural sources:

It can be found in avocados, chicken, mushrooms, and oats.

Signs of deficiency:

• Stomach pain
• Insomnia
• Mood changes
• Tingling in hands and feet

Dangers of overconsumption

Taking too much pantothenic acid is rare because your body will excrete the excess amounts through your urine.

Vitamin B6

Vitamin B6 exists in three major compounds, including

• Pyridoxine
• Pyridoxal
• Pyridoxamine

It can also exist in coenzyme forms, activating over 100 enzymatic reactions, including protein metabolism.

Functions

• Production of red blood cells and haemoglobin
• Production of neurotransmitters like serotonin and dopamine
• Boosts your immune system
• Metabolism and synthesis of amino acids, especially homocysteine
• Anti-nausea activity in pregnancy

Body requirements and absorption

The recommended daily intake of vitamin B6 varies.

Males and females between 19 and 50 should take 1.3 milligrams (mg).

Men who are over 50 years old should take 1.7 milligrams (mg). Women over 50 years old should take 1.5 milligrams (mg).

Pregnant and breastfeeding women should take 1.9 milligrams (mg) and 2.0mg, respectively.

Vitamin B6 is absorbed in your small intestine. The type of food you eat may affect the absorption of vitamin B6.

Natural sources

Bananas, walnuts, oats, almonds, turkey, and whole wheat bread are excellent sources of vitamin B6.

Signs of deficiency

• Microcytic anaemia – production of smaller-sized red blood cells due to lack of haemoglobin
• Insomnia
• Cracked lip
• Swollen tongue (glossitis)
• Peripheral neuropathy

Dangers of overconsumption

High doses of vitamin B6 can cause brain and nerve problems.

Vitamin B7

Vitamin B7 is popularly known as biotin. It is an essential enzyme in your body that breaks down food substances.

Functions

• Production of keratin for healthy nails, hair and skin
• Protein, carbohydrate and fatty acid metabolism
• Growth and development of your baby during pregnancy
• Regulating blood sugar

Body requirements and absorption

It is recommended that adults consume 30 micrograms of biotin daily. If you are a breastfeeding mother, you should take 35 micrograms daily. Biotin is majorly absorbed in the small intestine.

Natural sources

Sweet potatoes, spinach, liver, sardines, red meat and eggs are packed with biotin.

Signs of deficiency

Biotin deficiency is rare. However, you will notice:

• Thinning of hair
• Brittle nails
• Rashes and other skin issues

Dangers of overconsumption

There is no risk of overeating biotin from food.

Vitamin B9

Vitamin B9 exists in two primary forms:

• Folate, which is naturally occurring – in food
• Folic acid in synthetic forms – supplements

These forms of vitamin B9 are often used interchangeably.

Functions

• DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) production
• Production of red blood cells
• Your baby’s nervous system development during pregnancy
• Normal growth and functioning of tissues
• Protein metabolism with vitamin B12 and vitamin C

Body requirements and absorption

The recommended daily intake for teens and adults is 400 micrograms (mcg) daily. Breastfeeding mothers and pregnant women should take 400 and 600 mcg daily, respectively.

Vitamin C aids folic acid absorption in the small intestine and colon.

Natural sources

Oranges, lemons, beans, nuts, spinach, ugu (pumpkin leaf), and kidney beans are rich sources of folate.

Signs of deficiency

• Folate deficiency anaemia
• Neural tube defect, placental abruption and other complications in pregnancy

Dangers of overconsumption

Excess amounts of vitamin B9 are excreted through the urine. High amounts of vitamin B9 in supplements might interfere with certain medications.

Vitamin B12

Vitamin B12, or cobalamin, is the most structurally complex vitamin. Vitamins B6, B9, and B12 regulate homocysteine levels in your blood. Your body can store vitamin B12 in your liver for years.

Functions

• Maintaining healthy nerve cells and nervous system
• Production and regulation of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
• Formation of red blood cells
• Boosts memory, focus, and brainpower

Body requirements and absorption

Teens and adults above 14 should take 2.4 micrograms (mcg) daily. Vitamin B12 is absorbed in the small intestine.

Natural sources

Fish, meat, eggs, milk and fortified cereals are rich sources of vitamin B12.

Signs of deficiency

• Pale skin
• Numbness
• Megaloblastic anaemia – a condition in which large, immature red blood cells are produced

Dangers of Overconsumption

There is no risk of consuming too much cobalamin.

Vitamin C

Also known as ascorbic acid, vitamin C is a water-soluble vitamin. Vitamin C is popularly known for its powerful antioxidant properties.

Functions

• Boosts your immunity
• Biosynthesis of collagen
• Healing of wounds and burns
• Prevents inflammation by protecting cells from free radicals and oxidative stress
• Absorption of iron
• Strengthening and normal functioning of blood vessels
• Growth and repair of bone, skin, and connective tissues

Body requirements and absorption

Daily requirements vary based on age. The recommended daily amount for vitamin C is 75 milligrams (mg) daily for women and 90 mg for men. During pregnancy, it is 120 mg a day.

Vitamin C absorption is easier when consumed alongside foods rich in iron.

Natural sources

Citrus fruits like oranges, guavas, berries, mangoes, and vegetables like bell peppers and tomatoes are excellent sources of vitamin C.

Signs of deficiency

Vitamin C deficiency leads to scurvy. If you have scurvy, you might experience fatigue, connective tissue weakness, and swollen and bleeding gums.

Dangers of overconsumption

Vitamin C overconsumption is rare, but it can cause stomach upset.

Vitamin D

This is a fat-soluble vitamin that the body can also synthesize when exposed to sunlight. Another name for vitamin D is cholecalciferol.

Functions

It is necessary for:

• Mineralization of your bone
• Development, growth, and repair of teeth and bones
• Boosting your immune system
• Reducing the risk of autoimmune disease
• Absorption of calcium and phosphorus in your intestine
• Regulating levels of calcium and phosphorus in your blood

Body requirements and absorption

The recommended daily amount for vitamin D is 15 micrograms (mcg) daily. The equivalent in the International Unit (IU) is 600 IU.

Adequate exposure to sunlight is also necessary to attain optimal levels of vitamin D. The presence of dietary fat in your gut enhances its absorption. However, the small intestine absorbs vitamin D dietary fat.

Natural sources

Sunlight is the primary source of vitamin D. You can also eat sardines, eggs, yoghurt, and liver, which are rich in vitamin D.

Signs of deficiency

Weak bones, bone, and muscle pain are common signs of vitamin D deficiency, which can lead to:

• Rickets in children
• Osteomalacia or osteoporosis in adults

Dangers of overconsumption

Excessive intake can lead to hypercalcemia, causing symptoms like nausea, vomiting, and kidney damage.

Vitamin E

Vitamin E is a fat-soluble antioxidant that exists in various forms. It is also called tocopherol. The most biologically active form of vitamin E is alpha-tocopherol.

Functions

• Antioxidant and anti-inflammatory properties that reduce the risk of inflammation and diseases
• Formation of red blood cells
• Use and metabolism of vitamin K
• Boosts your body’s immunity
• Development of healthy skin

Body requirements and absorption

The daily requirements vary based on age. The recommended daily amount of vitamin E is 15 milligrams (mg) for people above 14 years old. For women who are pregnant and breastfeeding, the daily recommended intake is 15 mg and 19 mg, respectively.

Vitamin E is absorbed in the small intestine.

Natural sources

Nuts, seeds, spinach, egg yolk, and vegetable oils are rich in vitamin E.

Signs of deficiency

Vitamin E deficiency is generally rare. However, it can cause haemolytic anaemia, a condition that destroys blood cells in newborns. Other signs of vitamin E deficiency include:

• Nerve damage
• Retinopathy – a disease of the retina that can lead to loss of vision
• Muscle weakness

Dangers of overconsumption

Excessive vitamin E intake is uncommon, but high doses can prevent blood clotting. This can increase the risk of bleeding or haemorrhage.

Vitamin K

Vitamin K is popularly known as the blood clotting vitamin. It is a group of fat-soluble vitamins. It exists in two main forms:

• K1 – phylloquinone
• K2 – menaquinone phylloquinone

Phylloquinone is the main dietary form of vitamin K found in green leafy vegetables. Your body stores vitamin K in the liver, brain, heart, pancreas and bones. So, you may not need to eat large amounts of vitamin D.

Functions

• Blood clotting
• Healing of wounds
• The development of healthy bones and other connective tissues may have potential benefits for heart health

Body requirements and absorption

The daily requirements for vitamin K vary based on age.

Children between 9 to 13 years should take 60 micrograms (mcg). People between 14 to 18 years old should take 75 micrograms (mcg). Women who are pregnant and breastfeeding should take 90 micrograms (mcg).

Vitamin K is absorbed through the ileum and jejunum of the small intestine.

Natural sources

Ugu (pumpkin leaves), fermented soybeans, locust beans, e.g., ogiri and iru, cabbage and cow liver are rich sources of vitamin K.

Signs of deficiency

Difficulty with blood clotting, which would affect how your wounds heal.

Dangers of overconsumption

Overconsumption of supplements is rare, but excessive intake can interfere with blood-thinning medications like Warfarin, leading to blood clotting disorders.

Vitamins play diverse and vital roles in maintaining your health and overall well-being. It would be best if you had to understand each vitamin’s functions, sources, and recommended daily intake. It would help if you also remembered that balance is critical. This will ensure that your body functions optimally. Curate a diet filled with various foods, fruits, and vegetables rich in nutrients and flavour for a healthier, happier life.