The B Vitamins

This is the second post in my vitamin series. Vitamin A is here

The B-complex vitamins are water-soluble, meaning they need to be consumed on a daily basis because any excess passes through us quickly, whereas the fat-soluble vitamins are stored a little longer so we don’t have to be sure we are getting those every single day (fat-soluble vitamins = A, D, E, K; water-soluble vitamins = C, B). There are 8 b-vitamins:

  • B1 (thiamin): helps in the breakdown of glucose for energy, helps metabolize certain amino acids in the muscle, helps produce DNA, and helps make neurotransmitters (chemical messengers that send important messages throughout our nervous system). Good sources of B1 are: ready-to-eat cereals, enriched cereals and grains, whole-grain products, wheat germ, peas, asparagus, and okra. Both men and women can meet 100% of their RDA for B1 if they eat 3/4 cup of whole grain Total cereal. The RDA1 for men is 1.2mg/day and for women it’s 1.1mg/day.
  • B2 (riboflavin): helps metabolize carbs and fat; helps to fight against free radical damage; helps metabolize four other vitamins – folic acid, B6, vitamin K, and niacin. Enriched and fortified grains, green veggies such as broccoli, asparagus, and spinach are good sources. Similar to B1, you can meet the AI2 for men and women by consuming 3/4 cup of whole grain Total cereal. Men need 1.3mg/day and women need 1.1mg/day.
  • B3 (niacin): helps metabolize carbs and fatty acids for energy; helps DNA replication and repair. Good sources are cereals, legumes, seeds, leafy veggies, and tea. Similar to B1 and B2, 3/4 cup of whole grain Total cereal will fulfill your AI 100%. Men need 16mg/day and women need 14mg/day.
  • B5 (pantothenic acid): helps breakdown fatty acids. Sources include potatoes, oat cereals, tomato products, mushrooms, sunflower seeds, enriched rice, green peas, sweet potato, whole grains. Men and women need 5mg/day which is achieved by having 1/2 cup of whole grain Total cereal or with 1.5 cups of mushrooms.
  • B6 (pyridoxine): involved in many metabolic processes such as amino acid metabolism; making neurotransmitters; metabolizing carbs; creating heme (required to make hemoglobin); helping the immune system; metabolizing niacin, folate, and carnitine; and helping to reduce cardiovascular disease risk. Good sources are garbanzo beans, whole grain cereal, potatoes, peanut butter, bananas, asparagus, and carrots. One cup of garbanzos will provide you with 100% of your RDA. Men and women need  1.3mg/day.
  • B7 (biotin): helps metabolize fat, carbs, and protein; helps gluconeogenesis. Appears to be widespread in foods and does not have an official daily requirement.
  • B9 (folic acid): also called folate; helps the most basic cellular functions, such as making DNA; helps metabolize amino acids; helps create red blood cells. Good sources of folate are whole grain cereal, lentils, spinach, asparagus, green beans, peas, beets, cauliflower, broccoli, corn, tomatoes, romaine, pinto beans, rice, pasta, enriched flours and breads, corn meals, bananas, grapefruit, oranges, pears, pineapple, strawberries. You can meet your RDA 100% by eating 3/4 cup of whole grain Total cereal or by eating 1.5 cups of cooked lentils. Both men and women need 400 mcg/day.
  • B12 (cobalamin): helps metabolize an essential amino acid; helps make neurotransmitters, DNA, phospholipids; prevents buildup of homocysteine (related to risk of heart disease); metabolizes certain fatty acids; helps coat nerve fibers therefore  keeping the nervous system running well. Good sources for vegans are fortified cereal products, ready-to-eat cereals, fortified nut milks, and B12 supplements. Men and women need 2.4mcg/day, which you can get with less than one cup of fortified soy milk or with a half cup of Special K cereal. Pretty simple, right?–I don’t know what all the fuss is with meat-eaters worried about vegans’ consumption of B12!
Most B vitamins are destroyed with heat and light, and sometimes to air. Raw is the best way to go if possible. My nutrition textbook also provides tips to retain the vitamins when preparing foods:
  • Steam veggies and don’t let them actually touch the water, because the nutrients get carried away with the water
  • Cook at low temperature for a short amount of time. High temps especially kill vitamin C, thiamin, and riboflavin.
  • Cut fruits/veggies and store in airtight containers to avoid exposure to air.
  • Eat veggies and fruits whole, unpeeled, and raw whenever possible

1. RDA = recommended dietary allowances
2. AI = adequate intakes

Thompson, Janice & Manore, Melinda. Nutrition: An Applied Approach, 3rd Ed. Copyright (c) 2012 Pearson Education, Inc.

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