Nutrition Tuesday: Vitamins & Minerals

Vitamins and minerals are categorized as micronutrients, which some people might interpret as non-important. However, both vitamins and minerals are essential to life. Certain vitamins and minerals are more important and needed in larger amounts than others, but all are important in maintaining a healthy body.

Vitamins are organic substances created by plants or animals. Minerals are inorganic substance that come from the earth. Plants absorb minerals from the soil and water and humans and animals absorb minerals through consuming plants.

Vitamins are classified as either water soluble or fat soluble. Water-soluble vitamins easily dissolve in water and are easily excreted by the body and thus must be consumed in larger quantities and preferably on a daily basis. Fat-soluble vitamins are absorbed through the intestine with the help of fats and can be stored easier in the body and thus can be consumed in smaller amounts and less frequently (However, it’s still important to consume them!).

Human Vitamins

Water-Soluble Vitamins
Fat-Soluble Vitamins
Vitamin B1
Vitamin A
Vitamin B2
Vitamin D
Vitamin B3
Vitamin E
Vitamin B5
Vitamin K
Vitamin B6
Vitamin B7
Vitamin B9
Vitamin B12
Vitamin C

Now let’s look at a couple vitamins more in-depth:

Vitamin B12 is required by the body for proper red blood cell formation, neurological function, and DNA synthesis(1). It is the largest and most complex vitamin and cannot be synthesized by the human body and thus must be obtained through diet(2). Vitamin B12 is naturally found in animal products, including fish, meat, poultry, eggs and milk products. Many breakfast cereals are now fortified with B12. Since Vitamin B12 is found mostly in animal products, many vegetarians and vegans are in dangerous of having a vitamin deficiency. Nutritional yeast is a good source of Vitamin B12 for these populations. A Vitamin B12 deficiency can lead to megoloblastic anemia, fatigue, weakness, constipation, loss of appetite, and weight loss(1). The current Recommended Dietary Allowances (RDAs) for Vitamin B12 for adults is 2.4 mcg(1).

Vitamin C, or ascorbic acid, is vital for many physiologic functions within the human body. Humans cannot synthesize Vitamin C and must obtain it through diet. Vitamin C is important in the synthesis of collagen, which is one of the main components of tendons, ligaments, bones, and blood vessels(2). Another very important role Vitamin C plays is the production of carnitine. Carnitine is a transport molecule that transports fatty acids into the mitochrondria to be used for the production of energy(2). Vitamin C also has antioxidant properties. The current RDAs for Vitamin C is 90 mg/d for men and 75 mg/d for women(2). Vitamin C can be found in citrus fruit, tomatoes, spinach, and strawberries among other plants.

Vitamin D is a unique vitamin. There are several forms of Vitamin D, but Vitamin D3 is the primary form used by the human body(2). Cholesterol in the body can be convert into a precursor molecule to Vitamin D3 and then ultraviolet light from the sun converts the precursor molecule to Vitamin D3 in the skin. Only a minimal amount of sun exposure, about 15 minutes, can provide adequate Vitamin D3 for the human body.  

Minerals are chemical elements found naturally from the earth. There are 16 minerals that the human body requires to support human biochemical processes by serving structural and functional roles and also serving as electrolytes. Minerals include: potassium, chlorine, sodium, calcium, phosphorus, magnesium, zinc, iron, and several others. Let’s look at a couple minerals more in-depth:

Calcium is the most abundant mineral in the body. Calcium concentrations in the body are closely regulated by the body for normal cellular function. When calcium is deficient in the body, the body will absorb calcium from bone stores to maintain proper blood/cellular calcium concentrations(2). Most people think of bones when they think of calcium, however, calcium has another very important role within the body. Calcium is very important in cell signaling. Calcium ions are released during a nerve impulse to contract muscles. The current RDAs for calcium is 1000 mg/d for adults.

Iron is a component of hundreds of proteins and enzymes in the human body(2). Hemoglobin is the oxygen transportation molecule in red blood cells and it contains iron. Several important iron-containing molecules are found in the electron transport chain in the mitochrondria that are essential in creating ATP and energy for the body. Iron-deficiency anemia is a common condition that can occur when not enough iron is consumed in the diet. Low iron levels can also alter such processes such as the electron transport chain, neurotransmitter synthesis, and protein synthesis(2). Many studies have shown that iron intake of female athletes is low and thus making them more prone to iron-deficiency anemia(2). Iron levels can easily be determined by a simple blood test done by your health care provider.

Each vitamin and mineral has a specific role in the human body. It is important to consume the RDA of all the nutrients to ensure a healthy body. If you are concerned about your vitamin and mineral intake then please consider consulting with your health care provider and/or registered dietitian. They may suggest taking a vitamin supplement.

References:
1. CDC. Vitamins and Minerals. Available at: http://www.cdc.gov/nutrition/everyone/basics/vitamins/index.html.
2. Antonio J et al. Essentials of Sports Nutrition and Supplements. Totowa, IL: Humana Press; 2008.

(Disclaimer: As always this is for your information only. Please consult with your health care provider if you need any guidance with nutrition.)

Nutrition Tuesday: Overview of Macronutrients and Micronutrients

Last week we discussed the basics of metabolism. Now it’s important to discuss what nutrients fuel the body to not only get us through exercise, but our day-to-day activities for survival. Our bodies require two different types of nutrients: macronutrients and micronutrients. 
Macronutrients are carbohydrates, fats, and proteins, which ultimately provide the energy necessary to maintain body functions at rest and during physical activities and maintain the body’s structural and functional integrity1
Micronutrients are vitamins and minerals. As their names imply, macronutrients comprise most of a person’s dietary intake, while micronutrients are essential in much lower quantities. With the deficiency of micronutrients, athletic performance in addition to normal physiologic function will suffer. However, with a well-balanced diet, a person should not have to worry about any imbalances. 
Today’s post will give an overview of each type of nutrient required by the human body. The next few days this week I will post a more in-depth look at carbohydrates, fats, and proteins. Next week I will discuss vitamins and minerals.
The Macronutrients
Carbohydrates
Carbohydrates often get a bad name, but without question, wholesome forms of carbohydrates are the best choices for fueling your muscles and promoting good health. Carbohydrates, as their name suggests, are carbon-, hydrogen-, and oxygen-based molecules that are abundant in most plant foods, especially fruits and grains1. Not all forms and sources of carbohydrates are alike. The carbohydrate family includes both simple and complex carbohydrates2. Simple carbohydrates are monosaccharides (structurally the simplest form of carbohydrates) and disaccharides (two monosaccharides). Glucose, fructose, and galactose are monosaccharides or sometimes referred as the simple sugars2. The three most common disaccharides are sucrose (table sugar), lactose (milk sugar), and maltose (malt sugar)2
Complex carbohydrates are formed when sugars link together to form long complex chains, similar to a string of pearls. Plants store extra sugar in the form of starch, which is a complex carbohydrate. Humans store extra glucose mostly in the form of muscle glycogen and liver glycogen. This glycogen will become available for energy during exercise. 


The main functions of carbohydrates are:
  • The primary function is to provide energy to the cells of the body, particularly the brain
  • Facilitate the body’s metabolism of fat
  • Spare muscle protein
Fat
Lipid is the collective name given to a vast variety of water-insoluble chemicals, including fats and oils. Fat or lipids are made up of carbon, hydrogen, and oxygen atoms. The ratio of oxygen to carbon and hydrogen is much lower in lipids than in carbohydrates, and thus lipids are a more concentrated source of energy1. There are three major types of fatty acids that can be distinguished by their molecular bonds and number of hydrogens. Fats can be saturated (the maximum number of hydrogens), monounsaturated (having one carbon-carbon double bond), or polyunsaturated (having two or more carbon-carbon double bonds)1


The main functions of fats:
  • Fats provide many of the body’s tissues and organs (including the heart) with most of their energy. Fat is the ideal fuel because it contains almost twice the energy as glucose, weighs less, and is easily transported and stored1.
  • Essential for the transmission of nerve signals that generate muscle contraction.
  • Serve as a transporter for vitamins A, D, E, and K.
  • Provide cushioning for the prevention of vital organs and insulation from thermal stress of cold environments.
Proteins
Proteins are essential nutritionally because they are comprised of amino acids, which the body needs to synthesize its own proteins and nitrogen-containing molecules that make life possible1. Amino acids are the building blocks of proteins. There are 20 amino acids. Of these 20 amino acids, 9 are considered to be essential because the human body cannot synthesize these amino acids. The remaining 11 amino acids are considered nonessential because the human body can synthesize them. 


The main functions of proteins:
  • Produce antibodies for the immune system
  • Produce enzymes that are required for various chemical reactions in the body
  • Component of structural hormones:
    • Contractile proteins for muscle tissue (i.e. actin and myosin)
    • Fibrous proteins in connective tissues (i.e. collagen, elastin, and keratin)
  • Component of transport proteins (i.e. hemoglobin)
  • Component of peptide hormones (i.e. insulin, thyroid hormone, etc.)
  • Source of fuel when muscle glycogen levels are low due to prolonged intense exercise 
The Micronutrients
Vitamins     
Vitamins are metabolic catalysts that regulate biochemical reactions within the body2. They are found in plants that we eat and are created by the plants themselves. Vitamins are categorized into either water-soluble or fat-soluble vitamins. Water-soluble vitamins are found in the fluid portion of our bodies and do not accumulate to a large degree in the body1. Fat-soluble vitamins are stored in the lipid (fat) portion of our bodies and can accumulate in the cells1. Some vitamins include: Vitamin B6, Vitamin C, Vitamin D, and Vitamin A.
Minerals
Minerals are natural substances that plants must absorb from the soil2. The human body uses minerals for many different jobs, including building bones, making hormones, and regulating the heartbeat. There are two kinds of minerals: macrominerals and trace minerals3. Macrominerals include calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur3. Trace minerals include iron, manganese, copper, iodine, zinc, cobalt, fluoride and selenium3

References
  1. Antonio J et al. Essentials of Sports Nutrition and Supplements. Totowa NJ: Human Press, 2008.
  2. Clark N. Nancy Clark’s Sports Nutrition Guidebook, 4th Ed. Champaign, IL: Human Kinetics, 2008.
  3. MedlinePlus. Minerals. Available at: http://www.nlm.nih.gov/medlineplus/minerals.html. Accessed May 28, 2012. 
(Disclaimer: This is for your information. If you need help with your diet and developing healthy lifestyle choices then I suggest seeking out professional help from your medical professional or registered dietitian. If you see any errors, please let me know!)