B Vitamins include: B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate or folic acid) and B12 (cobalamin).
B vitamins perform a variety of important function in the body, they often work together to deliver a number of health benefits: enhance immune and nervous system function, support and increase the rate of metabolism, promote cell growth and division (including the red blood cells that help prevent anemia), maintain healthy skin and muscle tone, support the health of the heart and arteries and prevent neural tube birth defects (folic acid) to mention a few. B vitamins are also very interrelated. As mentioned above B2 is necessary for the activation of B6; B6 and B2 are necessary for the conversion of tryptophan to vitamin B3; B12 is necessary to convert Folic acid to its active form; B6 deficiency reduces vitamin B12 absorption and so on and so on. This is just to say that each plays an intricate role that can not be ignored. That is why B vitamins are often referred to as the Vitamin B complex.
The minimum recommended daily amount is 1.2 mg.
Food sources of thiamine: whole grains, brewer's yeast, oatmeal, brown rice, asparagus, kale, cauliflower, eggs, pork, beans and peas.B2 (riboflavin)
For the complete list of foods and thiamine content in them click here.
Deficiency causes beriberi, a disorder of the nervous system and the heart; it also leads to neurodegeneration, wasting and death. Poor diet, alcoholism and consumption of foods rich in anti-thiamine substances and thiaminase cause thiamine deficiency. Anti-thiamine substances are tea, coffee including decaffeinated, and betel nuts. Thiaminase (an enzyme that breaks down thiamine molecule) can be found in raw fresh water fish like carp and nardoo ferns which are not normally consumed by the general population in North America or Europe.
The minimum recommended daily amount is 1.3 mg.
Food sources of riboflavin: organ meats (liver, kidneys and heart), milk, yeast, cheese, oily fish, spinach, green peas, eggs, almonds.B3 (niacin)
For the complete list of foods and riboflavin content in them click here.
Deficiency symptoms include red and cracked lips, mouth and tongue sores, sensitivity to bright light, burning and itching of the eyes, and dermatitis.
The minimum recommended daily amount is 16 mg for men and 14 mg for women.
Food sources of niacin: tuna, salmon, swordfish, trout, mackerel, peanuts, corn, chicken, beef, lamb, brewer's yeast, beans, whole grains.
For the complete list of foods and niacin content in them click here.
Deficiency causes pellagra (a disease of "three Ds": diarrhea, dermatitis, dementia). Symptoms include reddish skin rash, weakness, tremors, anxiety, and confusion.
Toxicity:B5 (pantothenic acid)
Large doses in excess of 1,000 mg can cause liver damage.
The minimum recommended daily amount is 10 mg.
Food sources of pantothenic acid: yeast, liver, chicken, whole grains, avocado, raw mushrooms, trout, peanuts, lentils. Food processing can destroy pantothenic acid.B6 (pyrodoxine)
For the complete list of foods and pantothenic acid content in them click here.
Deficiency of pantothenic acid is extremely rare.
The minimum recommended daily amount is 1.7 mg.
Food sources of B6: chicken, fish, liver, kidney, pork, eggs, brewer's yeast, bananas, avocado, spinach. Food processing can destroy vitamin B6.
For the complete list of foods and vitamin B6 content in them click here.
Deficiency of B6 may play a role in heart disease, kidney stone formation, carpal tunnel syndrome and depression. Symptoms include poor appetite, dermatitis, anemia, susceptibility to infection.
High doses of B6 over 300 mg/day for long periods of time can cause nerve damage.
The minimum recommended daily amount is 30 mcg.
Food sources of biotin: tomatoes, romaine lettuce, almonds, eggs, onions, cabbage, cucumber, cauliflower, milk, raspberries, strawberries, oats, and walnuts.
For the list of select foods and biotin content in them click here.
Deficiency is rare; symptoms include hair loss, scaly skin rash (cradle cap in infants), muscle pain, high cholesterol, loss of appetite, nausea.
Toxicity has not been reported even at large doses.B9 (folate)
The minimum recommended daily amount is 400 mcg.
Food sources of folate: spinach, turnip greens, lettuce, dried beans and peas, sunflower seeds, liver, fortified cereals and pastas, peanuts, avocado, asparagus. When cooking, the use of steaming or of a food steamer can help keep more folate in the cooked foods, thus helping to prevent folate deficiency.
For the complete list of foods and folate (folic acid) content in them click here.
Deficiency of folate causes loss of weight and appetite, weakness, headaches, irritability. Pregnant women with folate deficiencies are at high risk of delivering babies with neural tube defects. Adequate intake of folate before getting pregnant and during the first four weeks of pregnancy (600 mcg/day) prevents this. Anemia is also a sign of folate deficiency in adults.
Toxicity is considered rare. However, one should avoid heavily fortified foods since large amounts of folic acid (synthetic form of folate added to foods and supplements) in excess of 1,000 mcg/day can mask anemia caused by vitamin B12 deficiency, thus allowing the problem to progress to the point of causing confusion, dementia and possible irreversible damage of the nervous system. In view of the above it is recommended to avoid foods fortified more than 100-200 mcg of folic acid which is 25%-50% of % Daily Value. Note that folate intake from unfortified foods (vegetables and fruits) is not a concern.
The minimum recommended daily amount is 2.4 mcg.
Food sources of B12: liver and organ meats, muscle meats, fish, eggs, shellfish, milk and most dairy products. Since the source of vitamin B12 is animal, vegetarians need separate B12 supplementation.
For the complete list of foods and B12 content in them click here.
Deficiency causes pernicious anemia, loss of nerve-insulating myelin, leads to elevated levels of amino acid homocysteine linked to the increased risk of heart disease. The loss of nerve-insulating myelin is referred to as a peripheral neuropathy - light to very painful tingling non stop in the hands and feet.
Here you can read in more detail about
vitamin B12 deficiency and its effect on immune health and glutathione.
Vitamin B12 is considered non-toxic, however, allergic reactions in the form of itching, rashes and diarrhea have been reported with high doses.