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Chapter 7 – Nutrition

Vitamins

Vitamins are organic compounds found in foods and are a necessary part of the biochemical reactions in the body.

Functions of Vitamins

They are involved in a number of processes, including mineral and bone metabolism, and cell and tissue growth, and they act as cofactors for energy metabolism.

You get most of your vitamins through your diet, although some can be formed from the precursors absorbed during digestion. For example, the body synthesizes vitamin A from the β-carotene in orange vegetables like carrots and sweet potatoes.

Types of Vitamins

Vitamins are either fat-soluble or water-soluble.

  • Fat-soluble vitamins:  A, D, E, and K, are absorbed through the intestinal tract with lipids. Vitamin D is also synthesized in the skin through exposure to sunlight. Because they are carried in lipids, fat-soluble vitamins can accumulate in the lipids stored in the body. If excess vitamins are retained in the lipid stores in the body, hypervitaminosis can result.
  • Water-soluble vitamins: The eight B vitamins and vitamin C, are absorbed with water in the gastrointestinal tract. These vitamins move easily through bodily fluids, which are water based, so they are not stored in the body. Excess water-soluble vitamins are excreted in the urine. Therefore, hypervitaminosis of water-soluble vitamins rarely occurs, except with an excess of vitamin supplements.

 

Recommended Intake

The RDA (Recommended Dietary Allowance) and the AI (Adequate Intake) are the amounts of a vitamin or mineral you need to keep healthy and stay well-nourished. They’re tailored to women, men, and specific age groups.The UL (Tolerable Upper Intake Level) is the maximum amount of daily vitamins and minerals that you can safely take without risk of an overdose or serious side effects. For certain nutrients, the higher you go above the UL, the greater the chance you could experience side effects as a result of intake.Spicy Original Beef Jerky | Matt-Hat Jerky 
The Food and Drug Administration uses a different measure for the nutrients you need: The DV (Daily Value) is the only measurement you’ll find on food and supplement labels. That’s because space is limited, and there’s a need for one single reference number. That number is the amount of a vitamin or nutrient that you should get for top health from a diet of 2,000 calories a day. The DV is sometimes the same as the RDA. Food labels show this as the percent of the DV provided for a 2000 calorie diet. Although the details may be different, both the RDA and DV are set up to provide intake guidelines that reduce risk of disease and other health problems caused by poor nutrition.
Vitamins, primary functions, and common sources:
Vitamins Primary Functions in the Body Common Sources
Vitamin A Regulates cell growth and differentiation, supports vision, and maintains skin and immune function. Liver, fish, eggs, dairy products, carrots, sweet potatoes, dark leafy greens.
Vitamin B1 (Thiamin) Converts food into energy, supports nervous system, and is essential for heart function. Whole grains, nuts, seeds, pork, fortified cereals.
Vitamin B6 (Pyridoxine) Involved in protein metabolism, red blood cell formation, and supports brain and immune system function. Fish, poultry, meat, fortified cereals, potatoes, bananas, chickpeas.
Vitamin B9 (Folate/Folic Acid) Essential for new cell synthesis, DNA production, and blood cell formation. Leafy green vegetables, liver, legumes, fortified grains, citrus fruits.
Vitamin B12 (Cobalamins) Helps make red blood cells, maintains a healthy nervous system, and assists in energy release from food. Meat, poultry, fish, dairy products, eggs, fortified cereals.
Vitamin C (Ascorbic Acid) An important antioxidant, supports collagen formation for tissue repair, and aids in immune resistance. Citrus fruits, berries, bell peppers, potatoes, broccoli.
Vitamin D Acts in a hormone-like manner, regulating mineral metabolism for strong bones and organs. Fortified milk and cereals, fatty fish.
Vitamin E Functions as an antioxidant, protecting cells from damage. Vegetable oils, leafy green vegetables, nuts, seeds, whole grains.
Vitamin K Essential for blood clotting and bone health. Cabbage, spinach, broccoli, kale, eggs, milk.

 

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Health and Fitness for Life Copyright © 2019 by Dawn Markell and Diane Peterson is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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