Water-soluble vitamins

Vitamin C (ascorbic acid)
The main source of vitamin C is food. Vitamin C is a strong antioxidant, therefore important for many oxidation and reduction reactions, protects vit. A, E, B1, B2, folic acid, and biotin from oxidation, increases Fe absorption, strengthens the body’s immunity, stops atherosclerosis. Vitamin C is necessary for bile production, drug and carcinogen metabolism.
Cases of hypovitaminosis occur in areas where daily diet lacks fresh vegetables and fruits. This manifests as poor wound healing, weakness, fatigue, bleeding from the gums.
It is recommended to consume 60 mg of vitamin C per day. Smokers have an increased need for vitamin C up to 80 mg/day.
It is believed that high doses of vitamin C (1-10 g/day) can prevent colds. There is no evidence to support this hypothesis. Vitamin C does not prevent illness, but it does alleviate and shorten its duration. Consuming large amounts can cause diarrhea and, over time, increase the risk of kidney stone formation.
Food sources of Vitamin C (in decreasing order)
Malpighia, blackcurrants, kiwis, guavas, parsley, blackberries, peppers, broccoli, Brussels sprouts, kiwifruit, strawberries, oranges, lemons.

Vitamin B1 (thiamine)
Thiamine is part of the composition of many coenzymes: it participates in the main metabolic processes of carbohydrates, proteins, and fats turning into energy; necessary for converting glucose into fatty acids. Consuming a lot of refined carbohydrates leads to hypovitaminosis. Consuming products rich in thiaminases (fish, seafood) also leads to thiamine deficiency. Alcohol, tobacco, coffee consumption, and products containing citric acid disrupt thiamine absorption. Avitaminosis is usually divided into cardiac and neurological. They rarely occur together. Cardiac – acute, manifested by heart and vascular insufficiency, frequent pulse, peripheral edemas, heart dilation. Neurological avitaminosis is characterized by a chronic form of the disease, accompanied by progressive peripheral neuropathy.
Food sources of Thiamine
Whole grain bread, yeast, legumes, nuts, pork and by-products, oats, wheat, buckwheat.
Recommended daily norm (RPN) – 1.2-1.6 mg/day.

Vitamin B2 (riboflavin)
Riboflavin is part of two important oxidoreductase coenzymes, which participate in many oxidation and reduction reactions, catalyze the metabolic processes of the Krebs cycle.
Vitamin B2 maintains normal skin and mucous membrane function, is important for vision. It participates in the metabolism of visual purple, which protects the retina from excessive ultraviolet radiation. It affects fat absorption and synthesis. Riboflavin is important for the formation of red blood cells, bone marrow function. It participates in Fe absorption.
Recommended daily norm (RPN) – 1.4-1.7 mg/day. A small amount of vitamin is produced in the intestines (synthesized by bacteria). More vitamin is needed during pregnancy, as well as when taking contraceptive preparations.
A deficiency of vitamin B2 causes cracks in the mouth and genital mucosa, stomatitis, cheilosis, glossitis, and “red tongue”, seborrhea, and damage to the tongue.
Riboflavin deficiency is often associated with a deficiency of vitamin B6, niacin, and folic acid.
Food sources of Vitamin B2
Milk and its products (except butter), eggs, liver, kidneys, brewer’s yeast, leafy vegetables. There is a lot of it in buckwheat, wheat, almonds, soybeans. Riboflavin is unstable, especially to ultraviolet sunlight.

Vitamin PP (niacin)
Niacin, also known as nicotinamide or nicotinic acid – both are obtained from food, but have different physiological functions. Approximately 50% of niacin is synthesized in the body from the amino acid tryptophan. 60 mg of tryptophan is equivalent to 1 milligram of niacin. It enters the composition of enzymes along with vitamin B2. A deficiency of niacin causes pellagra – a disease characterized by diarrhea, dementia, dermatitis.
– Dermatitis – an inflammatory skin reaction to sunlight. The neck area is most commonly affected.
– In cases of frequent bowel movements, there is often inflammation of the tongue.
– Symptoms of dementia range from mild mental and orientation disorders to manifestations of mania or even psychosis. Higher doses can cause hypotension.
Doses of 1-2 g/day are prescribed to treat hypertriglyceridemia and hypercholesterolemia.
Do not exceed the RPN for patients with gout.
Foods high in niacin:beef, pork, chicken, wheat flour, cornmeal, eggs, milk. The recommended daily norm (RDA) is 15-18 mg/day.

Folic Acid
Folic acid (pteroylglutamic acid) is a synthetic form of the vitamin, known in nature as folates. Folates are necessary for the production of proteins, DNA, and RNA. Along with vitamin B12, folic acid is required for the production of red blood cells.
A deficiency of the vitamin causes megaloblastic anemia. It is often a secondary hypovitaminosis caused by malabsorption, certain medication use, end of pregnancy, certain diseases including leukemia. It can also be a cause of infertility and diarrhea. Supplementing with folic acid has been shown to reduce neural tube defects. High doses reduce homocysteine concentration in the plasma.
Continuous use of anticonvulsant drugs is associated with a folate deficiency. Also, drugs that affect folate metabolism: cytotoxic chemotherapeutic agents (methotrexate, aminopterin), antimalarials (pyrimethamine), and antibacterials (cotrimoxazole).
Folic acid deficiency most commonly occurs when eating low amounts of fruits and vegetables, especially when they are cooked several times.
Dietary sources of folic acid (one serving – 50-100 micrograms)
Brussels sprouts, broccoli, cabbage, cauliflower, peas, asparagus, iceberg lettuce, beans, peas.
The recommended daily norm (RDA) is 300 μg/day. For pregnant women and those taking contraceptives, it is 400 μg/day.

Vitamin B6 (pyridoxine)
Vitamin B6 is involved in amino acid, hormone metabolism, erythropoiesis processes, and is also necessary for the immune system, essential for the metabolism of polyunsaturated fatty acids and carbohydrates.
Vitamin B6 deficiency is rarely detected. Hypovitaminosis more commonly occurs due to malabsorption, dialysis, alcohol consumption. Symptoms of vitamin B6 deficiency: inflammation of the mouth and tongue, cracks in the corners of the lips. Peripheral neuropathy can be a sign of vitamin B6 deficiency, but it can also be a lack of other vitamins, such as B1. Due to a deficiency of vitamin B6, hematopoiesis is disrupted, leading to sideroblastic (microcytic, hypochromic) anemia.
Dietary sources of vitamin B6
Meat, fish, whole grain bread, cereals, bananas, nuts, legumes, yeast, dairy products.
The recommended daily norm (RDA) is 1-1.4 mg/day.

Vitamin B12 (cobalamin)
Vitamin B12 (cobalamin) is the only vitamin found exclusively in animal products. Individuals with alcoholism and liver diseases have a high demand for this vitamin, as well as pregnant women. Pectin, a bulking agent found in apples and fruit juices, hinders the absorption of vitamin B12 in the intestines. Seaweeds, fermented cabbage, or yogurt contain bacteria similar to those in the intestines that can produce vitamin B12, but in small amounts.
Signs of vitamin B12 deficiency: most commonly, anemia (megaloblastic) occurs with a lack of this vitamin. Neurological problems can also arise. Vitamin B12 deficiency anemia is common in strict vegetarians and with a poor diet. Vitamin B12 starts to be lacking when the substances necessary for its absorption, called intrinsic (Castle’s) factor, decrease or are absent. This is characteristic of inflammation of the stomach mucosa, stomach cancer, after partial or complete removal of the stomach, and irritation, especially with alcohol. Sometimes, the absorption of vitamin B12 in the intestines is impaired (due to inflammatory or tumor damage to the ileum).
Dietary sources of vitamin B12
Meat and meat products, eggs, milk and dairy products, fish and fish products, yeast.
The recommended daily norm is 3 μg/day.

Vitamin H (biotin)
Biotin is produced by bacteria and yeast. It is obtained from food, and some is produced by intestinal bacteria. Biotin is involved in carbohydrate and fat metabolism.
Biotin deficiency often occurs in patients fed parenterally. Symptoms: skin flaking, inflammation of the tongue, hair loss, anorexia, depression, and hypercholesterolemia. Biotin deficiency can be caused by large amounts of raw egg whites containing avidin, a substance that breaks down biotin.
It is important to consume cooked eggs.
Dietary sources of biotin
Liver, kidneys, milk, dairy products, eggs, corn, oats, peas. The daily norm is not established because intestinal bacteria produce enough of this vitamin.

Pantothenic Acid
Very important for carbohydrate and lipid metabolism.
Signs of deficiency: burning sensation in the feet, depression, fatigue, vomiting, muscle weakness.
Food sources of Pantothenic Acid
Almost all food products: yeast, offal, peanuts, meat, eggs, vegetables.
This vitamin is not present in refined food products.
Recommended daily allowance (RDA) – 5–7 mg/day.

Source | Dietary Treatment in General Practice | Dietitian Doctor Jūratė Dobrovolskienė