Macrominerals

Calcium

Effects: Needed for the formation and maintenance of bones, teeth and healthy gums, stabilizes many body functions and has a natural calming and tranquilizing effect. It is necessary for maintaining a regular heartbeat, the transmission of nerve impulses, helps muscular growth and normal blood clotting.It also provides energy, breaks down fats, maintains proper cell membrane permeability, aids in neuromuscular activity, stops lead from being absorbed into bone and keeps the skin healthy. The correct ratio of calcium to phosphorus and magnesium is very important for a dog's health and needs to be carefully balanced - this is not something you would want to do without doing your research on the topic!
Deficiency: Signs of deficiency include lameness, bone demineralization, and an increased incidence of fractures. During lactation, signs include seizures and tetany (eclampsia).
Toxicity: Excess intake of calcium results in growth retardation and severe bone and joint abnormalities. When feeding a quality pet food, supplementation of calcium during growth is unnecessary, and potentially very dangerous.
Note: Excess calcium causes decreased phosphorus absorption (and vice versa!). Lack of magnesium in the diet renders calcium useless, because the body needs magnesium to properly absorb calcium. If adequate amounts of all 3 of these minerals are present int he diet, the body can regulate the balance according to its needs.
Sources: Raw bones (never feed cooked ones, they get brittle and may splinter!), bone meal (screen for heavy metal content before buying!), egg shell powder, leafy green vegetables, beans, blackstrap molasses, soy, sardines, salmon, nuts, cottage cheese, yogurt.

Phosphorus

Effects: Together with calcium, phosphorus is required for formation and maintenance of bones and teeth as well as most metabolic actions in the body, including kidney function, cell growth and the contraction of the heart muscle. Assists the body in vitamin use (especially some B group vitamins) and is also is involved in converting food to energy.
Deficiency: A deficiency of phosphorus is very rare. A sign of deficiency is depraved appetite.
Toxicity: Excess phosphorus ingestion usually results from feeding an all meat diet, which results in a calcium deficiency. Also promotes kidney damage.
Sources: Fish, meats (both muscle and organs), beans. Often too much in the diet is more of a problem than too little, so specific supplementation is not necessary.

Magnesium

Effects: Helps with formation of bone and teeth, maintains a healthy heart and assists the absorption of calcium and potassium. While calcium stimulates the muscles, magnesium is used to relax them. Also needed for cellular metabolism, absorption of calcium, vitamins C, E and B complex and the production of energy. It is also required for the production of enzymes and helps the body to rid itself of lead that has accumulated in bones and tissue due to environmental contamination.
Deficiency: Cardiovascular problems, weakness, seizures, hypertension. According to Earl Mindell's book "Nutrition & Health for Dogs" (pg. 45) convulsive seizures are often seen in dogs suffering from magnesium deficiency and can often be treated with a magnesium supplement.
Toxicity: Excess magnesium results in diarrhea and gas.
Sources: Wheat bran, whole grains, leafy green vegetables, meat, beans, bananas.

Sulfur

Effects: Formation and maintenance of skin, coat and nails, aids wound healing and detoxification of the body.
Deficiency: Coat discoloration, skin conditions (hot spots, eczema, dermatitis, allergies). Sulfur is absorbed in the intestine and a deficiency may occur when antibiotic treatment has destroyed the colony of intestinal bacteria, so feeding a probiotic supplement together with a sulfur supplement is beneficial. The best form of sulfur supplement is methylsulfonyl methane (MSM).
Toxicity: None reported.
Sources: Meat, fish, dairy products, eggs, blackstrap molasses.

Potassium and Sodium

Effects: These two minerals work together in so many body functions that they are listed here together. They are required to maintain fluid balance in the body cells, muscle functions, transmission of nerve impulses, heart activity and production of hydrochloric acid in the stomach.
Deficiency or imbalance of the two: fatigue/listlessness, poor growth, dry skin, loss of hair, muscular paralysis, dehydration, lesions on heart and kidneys.
Toxicity: Excessive sodium causes high blood pressure and loss of calcium in the body. Ecess potassium is generally not a problem unless the animal suffers from kidney failure.
Sources: meats, fish, whole grains, yogurt, bananas, sweet potatoes, squash, beans, tomatoes.

Microminerals

Boron

Effects: Utilized together with calcium and magnesium for building and maintaining bones. Enhances the body's ability to use calcium, magnesium and vitamin D.
Deficiency: Imbalance of calcium, magnesium and phosphorus, which may result in loss of bone mass and increased risk of arthritis.
Toxicity: Dry skin, digestive upsets.
Sources: brewer's yeast, broccoli, turkey, shellfish.

Cobalt

Effects: Production of red blood cells, aids iron absorption.
Deficiency: A lack of cobalt in the diet can lead to iron deficiency. Cobalt is found in cobalamin (vitamin B12), so a specific supplementation of cobalt is not necessary.
Toxicity: Damage to heart and thyroid gland, overproduction of red blood cells.
Sources: vitamin B12, meat, shellfish

Copper

Effects: bone growth and maintenance, conversion of iron into hemoglobin, immune function.
Deficiency: loss of hair and skin color, anemia, improper bone formation.
Toxicity: Liver damage.
Note: Some dog breeds are prone to copper storage disease, an inability to utilize and store copper properly. This can result in liver disease and other problems. It is important to watch the level of copper intake of these dogs and avoid additional amounts in supplements.
Sources: whole wheat, beef liver, nuts, beans, seeds, shellfish.

Fluoride

Amounts of fluoride required by the body are sufficient in a balanced diet and should not be supplemented.
Toxicity: arthritis, liver and kidney damage, bone malformation and cancer.
Note: many cities fluoridize their drinking water supply. It is beneficial for your pet's health to filter this water if they drink it on a daily basis.

Iodine

Effects: production of thyroid hormones which regulate the metabolism.
Deficiency/Toxicity: thyroid problems and resulting from that, impaired metabolism.
Sources: fish, sea salt, seaweed.

Iron

Effects: Required for the production of hemoglobin (together with copper, vitamin B12 and protein) and myoglobin and for the oxygenation of red blood cells. It also aids in maintaining a healthy immune system and energy production.
Deficiency: Iron deficiency results in anemia. Symptoms of iron deficiency may include fatigue, poor stamina, intestinal bleeding, nervousness, heart palpitations and shortness of breath.
Toxicity: Signs include weight loss, loss of appetite, and death. Iron oversupplementation can also contribute to reduced zinc absorption, heart disease and the hardening of arteries.
Sources: red meats, liver, beans, poultry.

Molybdenum

Effects: aids in processing carbohydrates, is required for normal cell function and nitrogen metabolism, protects the body from excess copper.
Deficiency: metabolic disorders accompanied by abnormal excretion of sulfur metabolites, low uric acid concentrations, and elevated hypoxanthine and xanthine excretion.
Toxicity: problems with the metabolism of copper in the body, diarrhea, anemia and slow growth.
Sources: liver, brewer's yeast, whole grains.

Silicon

Effects: aids the body with wound healing, fighting skin problems and infections, keeps bones, cartilage, tendons and artery walls healthy and supports the immune system.
Deficiency: teeth, bone and joint problems, hardening of the arteries. When dogs eat grass or dirt, they often have a need for additional silicon in their diet.
Toxicity: None known.
Sources: whole grains, beetroot, alfalfa, leafy green vegetables.

Manganese

Effects: necessary for the utilization of vitamin C, biotin, vitamin B1 and vitamin E. Required for normal reproduction, bone and cartilage growth, collagen formation, fat metabolism and production of fatty acids.
Deficiency: poor bone growth, problems with blood glucose levels, decreased reproductive performance, abortion, stiffness, and bone abnormalities.
Toxicity: rarely observed.
Sources: whole grains, nuts, peas, beets, leafy green vegetables, eggs.

Zinc

Effects: required for proper utilization of copper, B complex vitamins, vitamin A, calcium and phosphorus. Required for production of many enzymes, supports the immune system, improves antibody response, regulates white blood cells, aids protein digestion, is important for skin and coat health, protects the liver from heavy metal and copper damage. Together with vitamin C it greatly aids in wound healing.
Deficiency: skin problems, dry coat, excessive shedding, fading hair color, growth retardation, a weakened immune system, and poor reproductive performance.
Toxicity: Excess zinc intake results in vomiting, and may interfere with the absorption of other minerals such as copper and iron.
Sources: lamb, pork, liver, eggs, brewer's yeast, wheat germ, beans.