PART 2 OF A SERIES
Vitamins
Most of us have several bottles of vitamins of various types and descriptions. But what are they and why do we take them?
A vitamin is an organic compound that is essential for normal body function. These organic compounds are called vitamins if the body cannot make the compound in sufficient quantities, and it must be obtained through the diet. Different species have different requirements; vitamin C is essential for humans but horses have very low needs.
Thirteen vitamins are universally recognized at present. Vitamins are classified by their biological and chemical activity, not their structure. Thus, each “vitamin” refers to a number of similar compounds (vitamers) that all show the same biological activity. for example vitamin A includes the compounds retinal, retinol, and four known carotenoids. Vitamers by definition are convertible to the active form of the vitamin in the body, and are sometimes inter-convertible to one another, as well.
Vitamins have diverse biochemical functions and are essential for normal growth and development. This is particularly important in reproduction. Beginning at the time of conception the fetus develops using the available nutrients. Fetal development requires certain vitamins and minerals to be present at certain times. These nutrients facilitate the chemical reactions that produce among other things, skin, bone, and muscle. If there is significant deficiency in one or more of these nutrients, the fetus may not develop normally.
For the most part, vitamins are obtained with food, but a few are obtained by other means. For example, microorganisms in the intestine — commonly known as “gut flora” — produce vitamin K and biotin, while one form of vitamin D is synthesized in the skin with the help of the natural ultraviolet wavelength of sunlight.
Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs. Vitamins are used in many processes such as the conversion of food to energy.
Vitamins are classified as either water-soluble or fat-soluble. Vitamins A, D, E and K are fat soluble. These vitamins can accumulate in body and result in toxicity or hypervitaminosis. You can literally poison yourself by taking too many vitamins. But since the fat soluble vitamins can be stored, the body can use the stores to fuel the body. A deficient diet may not become apparent for some time.
Vitamins B and C are water soluble. Excess quantities are flushed out on the urine. Overfeeding does not produce toxicity however since these vitamins are not stored a more consistent dietary source is needed.
Vitamins are sensitive compounds. Many are effected by heat, sunlight and storage. Old hay and grain that has been stored for many months will not have the same profile that it did at the time of harvest. Hay that is soaked will lose much of the water soluble vitamins, sugars and carbohydrates that were present.
Deficiencies of vitamins are classified as either primary or secondary. A primary deficiency occurs when an organism does not get enough of the vitamin in its food. A secondary deficiency may be due to an underlying disorder that prevents or limits the absorption or use of the vitamin, due to a “lifestyle factor”, such as smoking, excessive alcohol consumption, or the use of medications that interfere with the absorption or use of the vitamin. People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency. In contrast, restrictive diets have the potential to cause prolonged vitamin deficits, which may result in often painful and potentially deadly diseases.
Well-known human vitamin deficiencies involve thiamine (beriberi), niacin (pellagra), vitamin C (scurvy), and vitamin D (rickets). In much of the developed world, such deficiencies are rare; this is due to an adequate supply of food and the addition of vitamins and minerals to common foods, often called fortification.
Thiamine
Let’s take a look at Thiamine, one of the B vitamins.
Thiamine is vitamin B1, it is a water soluble vitamin and cannot be stored in the body. In humans a deficiency of thiamine causes Beriberi, Wernicke-Korsakoff syndrome.
High doses in people causes drowsiness or muscle relaxation.
Foods that are excellent sources of thiamine include: pork, oatmeal, brown rice, vegetables, potatoes, liver, eggs. You’ll note that none of these food items are present in horse feed!
Thiamine or Vitamin B1, is important in carbohydrate metabolism and in the transmission of impulses along nerves (for this reason it is often used in calming supplements) The NRC has set a daily dietary requirement for Thiamine because, unlike most of the other B-vitamins, microorganisms in the intestine do not make enough Thiamine to meet the horse’s needs Fortunately fresh forage and cereal grains are good sources of this vitamin However, horses that are exercising or do not have access to pasture or fortified grains may need additional supplementation.
The B vitamins are a group of water-soluble vitamins, each with its own distinct use and chemical properties. Being water soluble means that they are not stored in the body, and so are rapidly excreted in the urine should there be an excess supply. Horses can to some extent rely on their own “home-made” B vitamins to meet their full requirements. While the horse manufactures his own niacin (formerly B3), the remaining B vitamins are produced as part of the mutual working contract between the horse and his bacteria of the hind gut. Any shortfalls in B vitamin production are supplemented through the diet by way of pasture and hay, provided there is ample supply. Vitamin B12 is the only B vitamin not produced in plants, and therefore the horse must rely on the supply from the hindgut bacteria.
Little research is available on the subject of vitamin B requirements in horses and what proportion of these are met by the horse’s naturally manufactured supply. While a horse will rarely show signs of deficiency, there may be times when a supplemental source of B vitamins can be the difference between meeting minimal requirements for health and optimal requirements for top performance. There are certain times when a B complex vitamin supplement may be beneficial due to a diminished supply from both internal and external sources. These include:
- Horses on high grain, low forage diets, or those on very poor quality forage
- Horses in high stress situations or during extreme exertion
- Horses with reduced appetite and general ill thrift due to illness or stress.
- Horses on broad spectrum antibiotics where hindgut bacteria will be compromised.
- Horses that have poor digestive health such as diarrhea or extreme parasite burden.
- Very young horses with incomplete gut microflora populations.
- Very old horses with diminished digestive efficacy.
B complex vitamin supplements have shown good results in the field for the performance horse and as an aid to the stress of travel and competition. Seeming to give the horse a natural lift, these supplements, though unproven by science, have a great following among experienced horse people. Some B vitamins have been studied more than others, and beneficial effects of feeding supplemental sources of these vitamins have been reported both in the academic press and in the field.
Some research has found that thiamine (B1), while being made in good amounts in the hindgut, is still required in the diet, but luckily thiamine is well supplied in green forage and other sources such as brewer’s yeast. Severe thiamine deficiency can occur when horses eat bracken ferns, but clinical deficiency is otherwise rare. Feeding higher levels of thiamine has historically been a remedy for calming the nervous horse. Though it won’t work for all horses, there is some evidence to suggest a calming influence in individuals that display undesirable behavior due to thiamine deficiency or increased requirement.
Most B vitamins are found in good quality fresh forage, which should always be the basis for a balanced diet. For horses doing light to moderate work, this is likely all that they will ever need. Supplying large quantities of B vitamins will not make a horse run faster and jump higher, but sometimes a supplemental source can help to supply optimal rather than minimal levels, and can allow the horse to perform to his full potential.
Brewers yeast can be an excellent source of B vitamins, but commercial supplements are also available with a consistent level of each of the vitamins. B vitamin supplements can be damaged by heat, light, and humidity. Furthermore, some B vitamins are incompatible with one another. Thiamine (B1) is incompatible with riboflavin (B2) and both are incompatible with cobalamin (B12) so in order for them to be fed together in a form that will work, some of these vitamins need to be coated for protection and to preserve activity and efficacy. In commercial supplements, the B vitamins are often coated with waxes, sugars, or gums to increase their stability and ensure consistent quality in each scoop given to the horse. If you are unsure whether your supplement contains coated vitamins, contact the manufacturer for further information. Many premixed feeds also contain coated B vitamins in their premixes, and if these feeds are used, further supplementation is rarely necessary if the feeds are fed at recommended rates.
Amino Acids
In contrast to vitamins, nobody has bottles or amino acids in their house….or do they? What are amino acids and why are they important?
Amino acids are biologically important organic compounds containing amine (-NH2) and carboxylic acid (-COOH) functional groups, usually along with a side-chain specific to each amino acid. About 500 amino acids are known and can be classified in many ways but their most important function is as the building blocks of protein.
Amino acids are critical to your horse’s health. There are 21 different amino acids used as building blocks to form proteins. Your horse needs all 21 of these building blocks to build those proteins in his body. The power of nature is such that a horse can create 12 of those amino acids himself without a dietary source. For the other nine, however, he’ll need some outside help.
The nine amino acids not created in a horse’s body are called the essential amino acids, which horses acquire through their food. In most circumstances all it takes is feeding your horses good-quality hay and commercial feed adapted to the horse’s age and activity level—and following the specific feeding instructions for that feed.
Many important amino acids play critical non-protein roles within the body. For example, in the brain, glutamate and gamma-amino-butyric acid (GABA) are, respectively, the main excitatory and inhibitory neurotransmitters. Hydroxyproline, a major component of the connective tissue collagen (tendons) is synthesized from proline. Glycine is used to synthesize porphyrins (hemoglobin) used in red blood cells.
Nine proteinogenic amino acids are called “essential” because they cannot be created from other compounds by the body and, so, must be taken in as food. These include: Arginine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine. Amino acids are the structural units that make up proteins. They join together to form short polymer chains called peptides or longer chains called either polypeptides or proteins.
Every protein in the body has a “recipe”. Let’s say for example that the body needs to make hoof wall. In order to make hoof wall the body needs lots of methionine. If the horse did not eat enough methionine the hoof wall will be inferior. It’s kind of like making a cake; if the recipe calls for 2 eggs, 1 cup of flour and a cup of milk but you only have 1 egg in the refrigerator the cake is not going to do well because the recipe is incomplete.
In young growing animals if there is not enough lysine the animal cannot make enough protein for growth, the result is a small, underdeveloped animal.
Amino acids are used for a variety of applications in industry, but their main use is as additives to animal feed. This is necessary, since many of the bulk components of these feeds, such as soybeans, either have low levels or lack some of the essential amino acids: Lysine, methionine, threonine, and tryptophan are most important in the production of these feeds. In this industry, amino acids are also used to chelate metal cations in order to improve the absorption of minerals from supplements, which may be required to improve the health or production of these animals.
Amino acids are also provided in grass, Horses do need more amino acids when they’re growing because they’re producing muscles, which are built from proteins. Likewise, as horses reach a very advanced age, they could also need additional amino acids to maintain muscle mass.
Tryptophan is an essential amino acid that is converted by the body into serotonin, melatonin and other hormones that transmit nerve signals in the brain. The effect of serotonin is to increase the feelings of well-being and contentment, to calm and to soothe.
Serotonin is related to sedation and lower levels of fear, stress, and aggression in humans as well as some animal species.
One of the sources of Tryptophan is turkey, hence the “Turkey Coma” associated with Thanksgiving. This substance may be included in calming products sold for use in horses, and there is some anecdotal evidence that it helps in producing quieter behavior.
Inositol is closely related to the B-vitamin family and is found in nearly every cell in the body. Because of its location within the cell membrane, it plays two major roles: transporting fats and assisting in nerve transmission. By participating in the action of serotonin, a neurotransmitter whose brain levels are known to be a factor in anxiety, inositol may be helpful in nervous horses.
Taurine is an amino acid found in high concentrations in electrically active tissues such as the brain, heart, retina and muscle. It stabilizes membranes and assists in the movement of electrolytes in and out of cells, which is critical for proper nerve transmission and muscle contraction. Taurine also acts as a detoxifier, is necessary for the absorption of fats and vitamins, and influences proper insulin and glucose levels. It can be found in supplements for growing horses, nervous horses and horses with metabolic issues.
Taurine occurs naturally in fish and meat. In cells, taurine keeps potassium and magnesium inside the cell, while keeping excessive sodium out. In this sense, it works like a diuretic. Because it aids the movement of potassium, sodium, and calcium in and out of the cell, taurine has been used as a dietary supplement for epileptics, as well as for people who have uncontrollable facial twitches.
According to animal studies, taurine produces an anxiolytic (calming) effect and may act as a modulator or antianxiety agent in the central nervous system by activating the glycine receptor. Taurine is added to many energy drinks to counteract the stimulant effect of caffeine.
Theanine is an amino acid analogue of the proteinogenic amino acids L-glutamate and L-glutamine and is found primarily in particular plant and fungal species. It was discovered as a constituent of green tea in 1949 and in 1950 was isolated from gyokuro leaves, which have high theanine content.
Theanine increases serotonin, dopamine, GABA, and glycine levels in various areas of the brain. Able to cross the blood–brain barrier, theanine has reported psychoactive properties. Theanine has been studied for its potential ability to reduce mental and physical stress, improve cognition, and boost mood and cognitive performance in a synergistic manner with caffeine.
I am certain you are in “brain overload” by now. In part 3 we’ll tackle the subject of herbal calmers! Thanks for reading!