These are inorganic elements that most animals need, and they are about 22 in total. Some, the macrominerals are required in more substantial amounts while the trace or microminerals.
The macrominerals include calcium, chlorine, sodium, phosphorus, potassium, sulfur and magnesium and here are the roles that each play.
Calcium and phosphorus
These two are significant components of the skeletal system (bone and teeth). Some of the roles that calcium does include heart function, maintaining electrolyte as a conjugate equilibrium in blood and it also helps in muscle contraction among others. Finally, a rabbit needs a constant calcium supply since their teeth are ever growing.
On the other hand, phosphorus is involved in energy metabolism. These two are very important in the rabbit’s diet, and you must also bear in mind their ratios. For instance, during growth and reproduction, the calcium to phosphorus ratio should be 2 to 1 while on maintenance, they can use a lower ratio. Note that "the minimum daily requirement for calcium of a medium-sized rabbit is about 510 milligram" 
Also, during pregnancy, development, and growth, they need higher amounts of these two minerals to help in the development of bones while adult ones will require lower amounts than any other life stage.
Since calcium is absorbed depending on the of calcium quantities in their diet, therefore, to retain the proportion of calcium and phosphorus, any excess calcium amounts taken in must be removed out thought their kidneys and finally expelled through their urine.
The white substance you usually notice in rabbit’s urine is calcium and excess amounts has been associated with kidney damages as well as urinary stones. Any calcium more than 15g/kg will result in soft tissue calcification and it may affect zinc and phosphorous absorption. Deficiency will also cause poor teeth and bone quality.
Also, phosphorous amounts that are more than 9g/kg are likely to reduce fertility and the intake of feed.
Calcium is often obtained from alfalfa and any other meal made from alfalfa while phosphorus comes from wheat bran and middlings and other grain byproducts. Note that grass hay has lower calcium than legume hay. Finally, A combination of alfalfa and grain byproducts can provide enough of these two minerals.
It works as a cofactor of several enzymic reactions and helps in nerve impulse transmission. It is also a significant bone component.
Deficiencies of magnesium are unlikely since it is rich in legumes such as clovers and alfalfa. Deficiencies are signaled by fur chewing while any excess must be eliminated through urine. Acceptable amounts range from 0.3 to 3 g/kg diet.
Sodium, chloride, and potassium
All these three are involved in the regulation of acid-base in all body fluids and blood. Individually, here are the roles they play:
- Potassium – It is a cofactor to several enzymes, and deficiencies symptoms include paralysis, respiratory distress, and weakness of muscles. Legumes including alfalfa contain abundant amounts of potassium and deficiency cases in rabbits are rare. Levels of 6.5 to 10 g/kg are often recommended.
- Chloride – The addition of into their feeds Lysine Hydrochloride makes it impossible for bunnies to lack chloride. Recommended levels are about 1.7 to 3.2 g/kg
- Sodium – No studies on sodium requirements in rabbits so far and the recommended levels are like the ones of sodium.
Sulfur is often found in amino acids such as cysteine and homocysteine. It is also found thiamine and biotin (vitamin B complex). It is necessary for the manufacture of these two amino acids in the cecum.
A deficiency of sulfur may reduce feed efficiency, affect microbial growth in cecum which will mean reduced fiber digestion. Acute deficiencies will cause weight loss, excessive salivating, loss of appetite, dullness and even death.
Microminerals or trace minerals
On the other hand, while microminerals include
- Copper – It is needed for iron to be absorbed usually and vital in energy metabolism, hair, and collagen formation. Deficiencies will cause anemia, abnormal bones, and hair graying for bunnies with a black coat and retarded growth.
- Chromium – It works as an activator of some enzymes that take part in the production of energy
- Cobalt – Forms a part of the vitamin B-12 structurally and the hindgut requires it to make vitamin B-12.
- Manganese –It is an amino acid metabolism coenzyme, and it helps in blood clotting as well as the formation of bones and cartilage. A manganese deficiency will cause low bone density, crooked legs, brittle bones as part of the malformed skeletal system.
- Fluorine – It promotes the formation of good teeth and bones
- Iodine – It is required in thyroxine hormone synthesis that occurs in the thyroid glands. Its deficiency often leads to goiter.
- Iron – It is essential in hemoglobin synthesis, a protein that transports oxygen to the cells and carbon dioxide from cells found in red blood cells. Deficiencies will cause anemia.
- Molybdenum – has several purposes and forms part of the rabbit’s teeth enamel
- Selenium – in conjunction with vitamin E, “leads to several abnormalities including Kashin-Beck disease which is an endemic and chronic degenerative osteoarthrosis.” Also, Supplementation by 0.1ppm does
helpsimprove birth and fetal weights as well as reducing atherosclerotic plaque formation.
- Zinc – It works as a vital cofactor of various enzymes, and it is also involved in the cell division process. Lack of zinc has been associated with effects on skin, hair, and bone
 de Blas, C., Wiseman, J. (2003). The Nutrition of the Rabbit. CABI Publishing, Oxon, UK.
 Turan, B., Balcik, C. & Akkas, N. Clin Rheumatol (1997) 16: 441. https://doi.org/10.1007/BF02238935
 Effect of selenium and vitamin E on the development of experimental atherosclerosis in rabbits Wójcicki, J. et