A Vitamin Primer - Important Things You Should Know About Vitamins
The first thing to know is that vitamins (along with minerals and amino acids) are considered “essential” nutrients, that is – you need them. So whether you get your vitamins from food or from supplement manufacturers like Kirkman®, knowing about these nutrients that make your body run is a good idea.
What Are Vitamins?
Vitamins are important contributors to normal metabolism or the chemical processes that must occur in your body to maintain life. Scientists have said that to be considered a “vitamin” the nutrient must be organic, that is, it contains one carbon atom in its molecular structure.
Only two vitamins can be produced by the body. These are Vitamin D-3, produced by the intake of sun on the skin and vitamin K, made in small amounts by friendly bacteria in the gut. Most of our vitamins come from plants and even vitamins from animal products, such as eggs, come from plants that were ingested by an animal or created by bacteria.
Vitamins are also associated with specific health conditions caused by a deficit of a vitamin nutrient. Vitamins are either fat-soluble or water-soluble. Fat soluble vitamins are absorbed through the intestinal tract and are stored in the fatty tissues of the body and the liver. They can stay in the body as reserves for days, some of them for months. Water soluble vitamins do not get stored in the body for long and are excreted in urine. They need to be continually replenished.
How Many Vitamins Are There? What Do They Do? What are Sources?
There are currently 13 recognized vitamins. Below is a list of vitamins and some of their key characteristics:
1. Vitamin A (0366-001) (Retinol, Retinal) – Promotes eye health
Sources: liver, cod liver oil, carrots, broccoli, sweet potato, kale, spinach, pumpkin, egg, apricot, cantaloupe and melon
Sources: yeast, pork, cereal grains, sunflower seeds, brown rice, kale, asparagus, cauliflower, potatoes, oranges, liver and eggs
Sources: cottage cheese, milk, yogurt, meat, eggs, fish, green beans, bananas, asparagus, okra and persimmons
Sources: mushrooms, asparagus, nuts, dates, tomatoes, fish, milk, eggs, whole-grains, brewer’s yeast, legumes and leafy vegetables
5. Vitamin B-5 (0095-200, 0499-007) (Pantothenic Acid) – Enables the use of fats, carbohydrates or protein as energy sources; aids in hormone production and promotes immune system health. Sources: root vegetables, leafy vegetables, mushrooms, turnip greens, fruit, legumes, meat, eggs and dairy
6. Vitamin B-6 (0268-100, 0291-120) (Pyridoxine, Pyridoxal, Pyridoxamine) – Promotes glucose and protein metabolism and the manufacture of hemoglobin for lymph nodes, thymus and spleen health; also, benefits the central nervous system.
Sources: salmon, carrots, meat, avocados, banana, leafy greens, legumes and nuts
7. Vitamin B-7 (0382-120) (Biotin, Vitamin H) – Supports the health of the skin, nerves, digestive tract, metabolism and cells.
Sources: egg yolk and liver
8. Vitamin B-9 (0016-400, 0040-200, 0275-200, 0293-180, 0425-180, 0477-120, 0478-060) (Folic Acid, Folinic Acid, 5MTHF) – Promotes healthy pregnancies and births; supports adrenal function and a healthy nervous system; also, necessary for key metabolic processes.
Sources: green vegetables, beans, asparagus, bananas, melons, legumes, yeast and mushrooms
Sources: fish, shellfish, meat, poultry, eggs, milk, dairy products, some fortified cereals and soy products
10. Vitamin C (0024-100/250, 0029-250, 0393-007, 0438-007, 0479-100/250) (Ascorbic Acid) – Helps form and maintain bones, skin and blood vessels and produces collagen, L-carnitine and neurotransmitters; also, metabolizes proteins and provides antioxidant activity.
Sources: fruits and vegetables
11. Vitamin D (0378-120, 0380-120, 0422-120, 0434-120, 0428-090) (Ergocalciferol (vitamin D-2), cholecalciferol (vitamin D-3) – Supports the immune system, brain and nervous system; also supports healthy bones and teeth.
Sources: fatty fish, beef liver, cheese, egg yolk and foods fortified with vitamin D, such as dairy products, orange juice and cereals
12. Vitamin E (0030-100/250) (tocopherol, tocotrienol) – Supports heart, brain and nervous system health.
Sources: avocado, eggs, milk, nuts, leafy vegetables, kiwi fruit, green vegetables, wheat germ and whole grains
13. Vitamin K (0498-120) (phylloquinone, menaquinone) – Supports proper blood clotting, bone metabolism and the regulation of calcium levels.
Sources: leafy vegetables like kale and swiss chard, parsley, kiwi fruit and avocado
How much do you need of each vitamin?
Here’s where your work gets complicated. A good practice is to enlist the help of your physician, registered dietitian or nutritionist for guidance when deciding what nutrients you need and in what amounts to support your good health.
There are also four official sources of information on the average requirements of vitamins (and minerals) for good nutrition. These are:
- RDA (Recommended Daily Allowance) tables - Prepared by the National Academy of Sciences, RDAs have historically been used as the basis of data for vitamins and minerals. RDAs are recommendations for average, safe and adequate amounts of daily nutrient intake by 97 per cent to 98 percent of healthy men, women, boys and girls in different age groups. Specific recommendations are also given for infants, children, teenagers, pregnant and breast-feeding women and adults through age fifty and adults over age fifty.
- DRI (Dietary Reference Intakes) tables- Prepared by the National Academy of Sciences, Food and Nutrition Board of the Institute of Medicine for both Americans and Canadians. DRI tables updates the RDAs for vitamins, minerals and includes many other nutrients. The DRI tables should eventually replace the RDA tables because they are more comprehensive. New in the DRIs was the establishment of the Tolerable Upper Intake levels (UL) for each nutrient as a guide to help decrease negative side effects that can develop from excessive intake of nutrients.
- DV (Daily Value) tables - Prepared by the U.S. Food and Drug Administration (FDA) for product labeling purposes.
- Foreign and international standards - Prepared by member nations of the United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO), the tables offer comparison standards between the U.S., WHO and Canada for vitamins and minerals.
- (You can find these tables under Resources on Kirkman’s website).
Food vs Supplements for Vitamins
In 2016, a study published in the Journal of the American Medical Association showed that the majority of American adults used dietary supplements. The Council for Responsible Nutrition (CRN) that has tracked the use of dietary supplements in the U.S. for more than 15 years, reported in 2016 that 71% of U.S. adults, or more than 170 million Americans, reported taking dietary supplements.
The popularity of dietary supplements as a source of vitamins, minerals and other nutrients reflects the public’s opinion that they can’t get enough of the nutrients they need from food. There is world-wide concern that our modern farming and food processing practices are adulterating and robbing the nutrients in our food supply. Additionally, busier lifestyles take many individuals in the direction of fast-food restaurants with their convenient staples of foods that are calorie-rich and nutrition poor.
Let’s not lose sight of the important issue, which is getting the nutrients you need. Dietary supplements provide a convenient and safe alternative to food to get those needs met.