Deficiency and excess of VITAMINS

Vitamin A

Vitamin A plays an important role in the proper functioning of the eye and the immune system, in maintaining fertility, in preventing miscarriage and in combating watering and dryness of the eyes, dry skin and acne.

Vitamin A deficiency is very widespread and occurs when the intake from food is insufficient; it can show itself through visual disturbances and the appearance of peeling, dry and thickened skin.

An excess arises as a result of excessive intake, particularly in people who drink heavily or who have liver disease, and can show itself through headaches, drowsiness or insomnia, hypercalcaemia, alopecia, muscle pain and a yellow-orange discolouration of the skin.

Sources of vitamin A are animal products (meat, fish, shellfish, liver, dairy products) and plant products (carrots, sweet potatoes, squash, onions, tomato purée, parsley, oregano, sage, nettles).

Vitamin B1

Vitamin B1 (thiamin) contributes to normal energy-yielding metabolism, to the normal functioning of the nervous system, to normal psychological function and to the normal function of the heart. Without enough thiamin, the cells can no longer use glucose properly to produce energy.

A vitamin B1 deficiency can occur with a high intake of refined carbohydrates, sterilised tinned food and diuretics, during prolonged feverish states or during antibiotic treatment. Insufficiently controlled diabetes and excessive consumption of mussels, shellfish, cucumbers, tea, coffee and horseradish can also be causes of a vitamin B1 deficiency.

The manifestations vary with each person's age, and in adults the symptoms can be: asthenia, apathy, irritability, insomnia, headaches, reduced attention and memory, atrophy of the muscle mass, palpitations, tachycardia, constipation, abdominal pain and the appearance of beriberi.

Vitamin B1 toxicity occurs very rarely, but intravenous administration of more than 100 times the dose can cause headaches, heart rhythm disorders and cramps, and with doses 1000 times higher death can occur.

Sources of vitamin B1 are: pork, wholegrain products, potatoes, brewer's yeast, dark flour, oats, nuts, soya, dried beans, peas, eggs, milk and fruit.

Vitamin B2

Vitamin B2 is also known as the *yellow cell pigment* and is called, depending on its source, riboflavin (in meat), lactoflavin (in milk), ovoflavin (in eggs) or hepatoflavin (in liver).

The role of riboflavin:

Contributes to the metabolism of proteins, lipids and carbohydrates as well as of vitamins B6, B12 and PP and of phosphates
It plays a part in cellular respiration
Stimulates the growth of the body and reproductive function
It plays a decisive role in fixing iron in haemoglobin, works synergistically with vitamin C, and its effectiveness increases in combination with nicotinamide and vitamin B6
It takes part in the protein syntheses that determine a good development of body weight
It plays a part in the visual adaptation to light

A vitamin B2 deficiency is rare, since the intake from food covers the body's needs as long as the proportion of proteins is balanced. In diabetes, stomach ulcers, the use of contraceptives or during physical and mental strain, an increase in the dose is necessary.

There are no data on the toxicity of vitamin B2.

Sources of vitamin B2 are dairy products, meat, fish, eggs, wholegrain products, brewer's yeast, dried pulses, green vegetables, colourful fruits and pollen.

Vitamin B3 (PP, niacin)

Vitamin B3 (niacin) is part of many enzymes and is needed, among other things, to make hormones. It contributes to normal energy-yielding metabolism, to the normal functioning of the nervous system and to the maintenance of normal skin and mucous membranes.

Vitamin B3 is contained in the structure of some enzymes involved in several oxidation-reduction reactions and takes part in the normal metabolism of cardiovascular and nerve tissue.

A vitamin B3 deficiency can occur with a vegetarian diet, in chronic kidney disease, in alcoholism, during antitumour chemotherapy or in disorders of intestinal absorption, and the symptoms of the illness are known as pellagra.

The manifestations of the illness are weight loss, asthenia, apathy, *crocodile skin* (swollen and reddened skin with blisters that can become infected), mouth ulcers, digestive disturbances, bad breath, delirium, restlessness, depression, tiredness, headaches and diarrhoea. People on a maize-based diet are more exposed to a vitamin B3 deficiency.

An excess of vitamin B3 has only been found when doses above 1 g a day are given as medication, in which case digestive problems occurred.

Food sources: lean meat, beef and pork liver, kidneys, fish, dairy products and cheese, eggs, brewer's yeast, cereals, pollen, dried pulses, vegetables and fresh fruit.

Vitamin B5 (panthenol)

Vitamin B5 (pantothenic acid) contributes to normal energy-yielding metabolism and to normal mental performance, and is needed to make steroid hormones, vitamin D and some neurotransmitters. It also contributes to the reduction of tiredness and fatigue.

Signs of deficiency appear above all in people who consume alcohol, caffeine or sleeping pills, in people with raised cholesterol, during physical or mental strain, in older people, during intensive antibiotic treatment or when eating over-processed industrial foods. Symptoms in this case can be: chronic tiredness, tingling in the palms, muscle cramps, insomnia, depression, headaches, heart instability, allergies, arthritis, gout, low immunity and grey hair.

An excess of vitamin B5 leads to mild gastrointestinal disturbances or diarrhoea only at very high doses.

Sources of vitamin B5: meat, beef offal, wholegrain products, nuts, peanuts, royal jelly, mushrooms, cauliflower, green vegetables, egg yolk and brewer's yeast.

Vitamin B6 (adermin)

Vitamin B6 contributes to normal red blood cell formation, to normal protein and glycogen metabolism, to the normal function of the nervous system and the immune system, and to the reduction of tiredness and fatigue.

A lack of vitamin B6 does not cause any illnesses or specific symptoms, but alcohol abuse and psychotropic drugs destroy most of these vitamins.

The role of vitamin B6:

Takes part in iron metabolism
It is indispensable for a good absorption of vitamin B12
It contributes to the normal functioning of the nervous system and to normal psychological function
It contributes to the regulation of hormonal activity
It contributes to normal homocysteine metabolism

An excess of vitamin B6 has been found when more than 600 mg a day is given, showing itself through bone pain, muscle weakness and shivering in the fingers and toes.

Sources of vitamin B6: meat and meat products, brain, liver, kidney, milk, eggs, salmon, tuna, dried pulses, green leafy vegetables, brewer's yeast, bran and wheat germ, raw rice, maize, barley, oats, peanuts, nuts, potatoes, peas, cabbage, lettuce, spinach, avocado, melon, bananas, grapes, pears, pollen, walnuts and peanuts.

Vitamin B7 (biotin)

Vitamin B7 is vital for healthy hair and nails and for keeping the skin healthy by regulating its lipid content. It takes part in fat and carbohydrate metabolism, is used in the biosynthesis of hormones and is involved in the proliferation of the lymphocytes of the immune system.

A vitamin B7 deficiency occurs in malnutrition, alcoholism, zinc deficiency, digestive disorders and when taking sulphonamides, anticonvulsants or antibiotics, and it shows itself through massive hair loss or alopecia, flaking, muscle pain, depression, hallucinations, dry skin, eczema, nausea, asthenia, anaemia, raised lactic acid levels and depigmentation of the skin around the eyes. The absorption of biotin is prevented or slowed down by raw egg white, chlorinated water, oestrogens and alcohol.

An excess of vitamin B7 is excreted through urine and sweat, and dermatitis or allergic reactions can occur rarely.

Sources of vitamin B7: egg yolk, poultry meat and especially offal, fish, beef liver, soya flour, milk, peanuts, brewer's yeast, cabbage, mushrooms, peas, carrots, tomatoes, spinach, raw rice and fresh fruit.

Vitamin B9 (folic acid)

Vitamin B9 is indispensable in protein metabolism, plays a very important role in the intrauterine period, is involved in the production of red blood cells and stimulates the production of hydrochloric acid in the stomach; it is absorbed in the small intestine, and this depends on the presence of vitamin B12.

A vitamin B9 deficiency occurs in people with eating disorders, when excretion is increased, in people who eat food prepared at high heat or in people who drink large amounts of alcohol every day.

Signs of a vitamin B9 deficiency can be:

In children: delayed growth (congenital malformations);
In adults: changes in the digestive tract (digestive disturbances, diarrhoea, anorexia), a weak pulse, low resistance to infection, pallor with skin pigmentation, grey hair, nails that become hard and brittle, difficult wound healing, tiredness, drowsiness, a depressive state, memory disturbances, irritability and mental confusion.

A deficiency, but also the excessive use of some medicines that affect the absorption of vitamin B9, in the first trimester of pregnancy increases the risk of congenital malformations.

An excess of vitamin B9 can reduce the body's ability to absorb other vitamins and minerals, worsen intestinal complaints and, during pregnancy, when given excessively to pregnant women, increase the risk of asthma in children.

Food sources of vitamin B9 are: spinach, asparagus, broccoli, cucumbers, carrots, cabbage, green beans, potatoes, eggs, meat (kidneys, muscle), dark bread and brewer's yeast.

Vitamin B12 (the red vitamin)

Vitamin B12 is essential for the smooth working of the immune system. It also plays an important role in protein synthesis, in the metabolism of carbohydrates and lipids, in making it easier to release folic acid, in keeping the nervous system healthy, in reducing irritability, in increasing the ability to concentrate and in improving memory and mental balance .

A high intake of vitamin C (500 mg) leads to unwanted reactions in the absorption or bioavailability of vitamin B12.

Sources of vitamin B12: chicken, pork, beef, liver, kidneys, fish, eggs and dairy products.

A strictly vegetarian diet increases the risk of a vitamin B12 deficiency. Symptoms of a deficiency are: weakness, tiredness, yellow skin, anaemia, memory loss or difficulty concentrating and balance disorders.

An excess of vitamin B12 is found with supplementation for therapeutic purposes or can be caused by its release from an internal store (in illnesses such as leukaemia, hepatitis and cirrhosis of the liver).

Vitamin C (ascorbic acid)

Vitamin C is one of the body’s most important antioxidants. It contributes to the normal function of the immune system and to the protection of cells from oxidative stress, and increases iron absorption. Vitamin C is protected from oxidation by vitamins A and E and more of it is excreted during heavy physical effort. Cooking destroys 25–90 % of it, and it is also easily lost when fruit and vegetables are left in water for a long time.

Vitamin C contributes to normal energy-yielding metabolism and to normal collagen formation for the normal function of skin, gums, bones, cartilage and blood vessels, and contributes to the regeneration of the reduced form of vitamin E.

A vitamin C deficiency arises with high-protein diets or with a diet of excessively heat-treated products combined with foods low in raw ingredients; muscular effort and cold increase the need for vitamin C. There is a risk of deficiency especially in winter and spring. Taking vitamin C supplements should be accompanied by taking Mg, vitamin B6 and water, in order to rule out the risk of forming uric acid or oxalic acid stones. The symptoms of a vitamin C deficiency are:

Capillary resistance falls because of a disorder of collagen synthesis, and as a result periosteal, intramuscular, gingival, nasal and cutaneous bleeding occurs
The skin on the body dries out and yellow, green and red bruises appear on the lower limbs
Anaemia arises because of reduced iron absorption
The tooth sockets deteriorate, the gums recede and the teeth can fall out
Fractures are harder to heal, bone ends are soft and thickened, muscles become stiff, wounds heal only with difficulty
Reduces the body's resistance to toxins

An excess of vitamin C occurs only with additional medication and can show itself through: osmotic diarrhoea, disturbances in the absorption of B vitamins, sterility and miscarriage.

The need for vitamin C is not covered if raw food is avoided, since a large part of it is destroyed by heat preparation.

The main source of vitamin C is raw vegetables (cabbage, cauliflower, tomatoes, peppers, spinach, parsley, dill, tarragon) and fruits (rosehips, sea buckthorn, currants, strawberries, citrus fruits, chestnuts). Animal products contain small amounts of vitamin C, most of which is destroyed by heat preparation.