Vitamin B Complex: Its Benefits, Uses and Risks
Vitamin B complex refers to a class of water-soluble vitamins that play an important role in cell metabolism. They help in utilizing the energy obtained from fats, proteins and carbohydrates. However, they cannot provide the body with energy on its own. Read on to know more about vitamin B complex deficiency, benefits and side effects!
What does vitamin B complex do?
The vitamin B complex functions as coenzymes to other enzymes required in metabolic processes. An enzyme cannot function without its coenzyme. Hence, vitamin B complex deficiency leads to metabolic disorders in our body.
The vitamin B complex contains 8 vitamins namely thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6, biotin (B7), folate (B9) and vitamin B12. These vitamins have chemically different structures and are often found in the same foods.
- Thiamine acts as a coenzyme for enzymes involved in the metabolism of carbohydrates and amino acids.
- All plant and animal tissues contain thiamine; hence it is present in natural unprocessed foods. Some thiamine-rich vitamin B complex foods are oatmeal, whole-grain cereals, pulses, nuts, lean pork, heart, kidney, and liver.
- The Recommended Daily Allowances (RDA) of thiamine is 1.2 mg/day for men and 1.1 mg/day for women. Excess consumption of thiamine has no adverse side-effects. Hence no upper limit for consumption is defined.
- Thiamine deficiency severely affects malnourished and alcoholic individuals. Prolonged deficiency of thiamine can cause the disease beriberi. Common symptoms of beriberi include loss of appetite, pain in limbs, weakness, and damage to the nervous system as well as the heart.
- Riboflavin also functions as coenzymes in different biochemical reactions. The coenzymes participate in numerous oxidation-reduction reactions and energy metabolism in the body.
- Riboflavin is stable to heat and cooking does not destroy it easily. Some sources of riboflavin-rich vitamin B complex foods include dark green leafy vegetables, milk and milk products, liver, fortified grain products, whole grains, and cereals.
- The RDA of riboflavin is 1.3 mg/day for men and 1.1mg/day for women. Similar to thiamin, there is no defined upper limit for riboflavin consumption. Excess consumption is, therefore not harmful.
- Riboflavin deficiency can occur due to nutrient deficiencies, kidney problems, and liver disorders. Ariboflavinosis is a riboflavin deficiency causing sore throat, chapped lips, and scaly skin among a few other symptoms. Riboflavin deficiency can also cause symptoms such as inflammation of the mouth, eyes, skin and GI tract.
- Nicotinamide is the major form of niacin in our blood. The coenzyme forms of niacin participate in several metabolic reactions and play a critical role in the metabolism of glucose, fat and alcohol in our body.
- The RDA for niacin is given in niacin equivalents (NE). This is because dietary tryptophan (an amino acid) also helps fulfil our daily niacin requirements. The RDA for men is 16mg NE/day and for women is 14mg NE/day.
- Some niacin-rich vitamin B complex foods are poultry, tomatoes, potatoes, mushrooms, legumes, and whole grains. Dietary tryptophan can provide half the daily niacin requirement. Large doses of supplements containing niacin can have adverse effects such as flushing (redness, itching or tingling sensation), pain, rash, vomiting, nausea, headache and diarrhoea.
- Niacin deficiency can occur due to malnutrition, alcoholism, and hereditary disorders. Severe niacin deficiency can cause the disease pellagra. Common symptoms of this disease are dementia, dermatitis, diarrhoea, inflammation, hyperpigmentation and eventually death if left untreated.
Pantothenic acid (B5)
- Pantothenic acid plays an important role in several metabolic processes and helps in the metabolism of carbohydrates, fats and amino acid. It also has a significant role in the synthesis of lipids, neurotransmitters, steroid hormones, and haemoglobin.
- The Adequate Intake (AI) for pantothenic acid for adults is 5mg/day. Vitamin B complex foods rich in pantothenic acid include chicken, beef, potatoes, oat cereals, tomato products, liver, kidney, yeast, egg yolk, broccoli, and whole grains.
- Pantothenic acid deficiency is rare. The symptoms of pantothenic acid deficiency include vomiting, muscle cramps, hypoglycemia, nausea, depression, and increased sensitivity to insulin.
- Supplementation of pantothenic acid has no severe side effects. The supplemental form of pantothenic acid is calcium pantothenate which is used as dietary supplements.
- Vitamin B6 occurs in several different forms all of which converts into the coenzyme pyridoxal phosphate (PLP), which helps in amino acid metabolism. The ability of PLP to add and remove amino groups also makes it useful in protein and urea metabolism. Vitamin B6 is also crucial for normal growth, homeostasis, development and maintenance of the immune system.
- The Recommended Dietary Allowances (RDA) for vitamin B6 is 1.3mg/day for adults. We can lose Vitamin B6 from foods due to processing, freezing, cooking and drying. Vitamin B complex foods rich in Vitamin B6 are fortified breakfast cereals, chickpeas, potatoes, banana and pork.
- A person suffering from Vitamin B6 deficiency will also have other vitamin B inadequacies as well. Vitamin B deficiency can lead to a poor synthesis of neurotransmitters, depression, ulceration, scaly dermatitis and confusion. People suffering from liver disease, type 1 diabetes, systemic inflammation, and rheumatoid arthritis and alcoholics and elderly are at an increased risk of vitamin B6 deficiency.
- The upper – level intake of vitamin B6 is 100mg/day. A higher consumption can be dangerous because it can cause neurological damage in people. Common symptoms of overconsumption include depression, headaches, skin lesions, irritability, and muscle weakness.
- Biotin plays an important role as a coenzyme and supports various metabolic pathways of our body. Some researchers also suggest biotin to be useful for healthy skin, better nail and hair growth.
- The Adequate Intake (AI) of biotin for adults is 30µg/day. Some food sources rich in biotin include liver, egg yolks, soybeans, fish, and whole grains. Some bacteria present in our gastrointestinal tract also produce biotin.
- Biotin deficiency is rare if you maintain a healthy and balanced diet. Deficiency symptoms include depression, lethargy, hallucinations, tingling sensation in the arms and legs, hair loss, and scaly rash around the eyes, mouth and nose.
- Excess consumption has no known side effects. Hence, there is no upper limit for biotin consumption.
- The primary coenzyme form of folate is THF (tetrahydrofolate). THF plays a part in the synthesis of purines and pyrimidines, the base constituents of the DNA. Thus, folic acid is crucial for proper brain function and plays an important role in mental and emotional well-being. It works along vitamins B6 and B12 and other nutrients to control blood levels of the amino acid homocysteine.
- It is common to have low levels of folic acid. Alcoholism, inflammatory bowel disease and celiac disease can cause folic acid deficiency. Common symptoms include poor growth, tongue inflammation, gingivitis, loss of appetite, shortness of breath, diarrhoea and irritability.
- The folate derived from supplements can be used by the body more effectively than the folate derived from foods. Thus, folate intakes and requirements are often expressed as dietary folate equivalents (DFE).
- The RDA of folate for adults above 19years is 400 µg DFE/day. Some folate-rich foods are leafy greens, asparagus, brussels sprouts, citrus fruits and beets.
- There folate requirement of women increases during pregnancy. However, excess folate from fortified foods and supplements can delay the diagnosis of this vitamin B complex deficiency which can lead to neurological damage.
- Cobalamin plays an important role in the synthesis of DNA and RNA and in the regeneration of the amino acid methionine with the help of the trace element cobalt. Vitamin B12 helps in the growth and protection of nerve fibres. Bone growth also depends on vitamin B12 at a cellular level.
- The RDA of vitamin B12 for adults is only 2.4 µg/day. Anyone who consumes reasonable amounts of animal products is virtually guaranteed adequate amounts of vitamin B. Vegans can, however, consume fortified soy milk or even resort to artificial supplements.
- Like all water-soluble vitamins, vitamin B12 is susceptible to degradation while cooking. Microwave cooking reduces these losses significantly.
- Cobalamin deficiency can cause pernicious anaemia, neurological symptoms, impaired cognitive performance, fatigue, constipation and even advanced neurological symptoms.
- Excess consumption has no reported side effects. Hence, no upper limit for cobalamin consumption is determined.
Thus, a balanced diet rich in macronutrients and other micronutrients is essential to lead a healthy lifestyle and live a disease-free life! The use of vitamin B complex supplements should be discussed with your doctors to avoid serious side-effects and treat the deficiency promptly.