Micronutrient is a broad term which includes various vitamins, minerals and trace elements that are required for the synthesis of several biochemicals in the human body like proteins, enzymes and hormones. These biochemicals are vital for the maintenance of the normal physiological functions of the body. A nutritionally balanced diet includes adequate quantities of proteins, fatty acids and micronutrients which plays an essential role in regenerative processes, helps in coping with oxidative stress and preserves health of all metabolically active tissues. The trace elements and vitamins also impact all aspects of immune functions and a subclinical deficiency of these micronutrients impair immune functions thereby increasing the risk of infections. [1]

The oral cavity is the gateway to the body and its component cells and tissues constitute a unique organ system. Being a complex system, oral cavity’s health and function are influenced by various factors. One of the factors is the diet and nutrition, and any deficiency or excess of micronutrients adversely affect the oral health. This is a two-way relation and hence, any kind of dental disability directly or indirectly affects the nutritional status of an individual by hampering one’s ability to eat nutritious food. 

Though the role of micronutrients on general health has been investigated for years but evidence for its impact on oral health is still under research. In this review an effort has been made to highlight and emphasize the functions of micronutrients and their relation with oral health.

Role of micronutrients in oral health

Micronutrients have a multitude of functions in the human body, poor nutrition can lead to increase vulnerability to various oral and systemic diseases. Diet and nutrition aids in promoting the growth of craniofacial, dental and periodontal structures. [1] 

Vitamins

Vitamins in diet play an important and equivocal role in general and oral health. Vitamins are the organic compounds that are required in little quantities for the optimum functioning of cellular processes and regular preservation of individual’s health. [2] Vitamin B complex comprises of eight chemically and pharmacologically distinct vitamins which act as precursors for various coenzymes in different metabolic processes.[3] Mustafa et al., 2013 suggests that vitamin B supplementation could hasten post-surgical healing.[4]

Vitamin C plays a crucial role in the formation and maturation of collagen and maintaining the integrity of osteoid tissue and dentin. Its deficiency leads to scurvy that interferes with wound healing.[3] It was observed by Freeland-Graves et al., in 1991 that vitamin C supplementation could help with the symptoms of scurvy like gingival bleeding and inflammation. [5]

Vitamin D regulates calcium and phosphate metabolism in the body to maintain their sufficient plasma levels that are required for adequate mineralization of bone.[3] Local application of vitamin D was reported to accelerate post-surgical healing and osseointegration in the oral cavity by Staudte et al., 2010; Mustafa M et al., 2013; Lee JH et al., 2017. [3,4,7] Although most of the vitamins have a direct effect on oral health but evidence suggests that vitamin A supplementation has no effect on periodontal health. [8]

Minerals

Minerals are inorganic compounds that form crystals and are required for enzyme activity, preservation of fluid balance, formation of bone tissue, synthesis of hormones, transmission of nerve impulses, relaxation of muscle and act as anti-oxidants.[2]

Calcium

Calcium is vital for the proper development and maintenance of hard dental tissues, the bony sockets and the jaw bones. Calcium helps to maintain the mineral composition of teeth, which are subject to both demineralisation and remineralisation processes. Primary teeth mineralisation begins around 4 months in-utero and that of permanent teeth around birth, which continues till 6-13 years of age. [9] Therefore, any imbalance in Calcium uptake will hamper the growth and development of tooth during gestation and childhood. Apart from the effect of calcium on hard dental tissues research has shown that the local administration of calcium improves osseointegration and calcium supplementation improves non-surgical periodontal treatment results. [2]

Phosphorous

Phosphorous being the second most abundant mineral in body after calcium is essential for tooth calcification. Deficiency of phosphorous has shown to result in failure of dentin formation and increased caries susceptibility. [10]

Magnesium

Magnesium is the third most abundant mineral in teeth, with dentin containing two times the amount present in enamel.[10] Magnesium is essential for energy metabolism with its primary role of regulating the enzyme activity of 300 enzymes.[1] Its deficiency is suspected to trigger apoptosis and the symptoms can range from muscle cramps, muscle twitching to the onset and progression of periodontal disease. Magnesium supplementation also enhances the non-invasive periodontal treatment results.[2]

Zinc

Zinc, copper and magnesium act as essential metabolic cofactors for enzymes involved in the synthesis of bone matrix and are significant for bone health. Zinc is a trace element present in all tissues and body fluids whose deficiency reduces epithelialization rate, wound strength and synthesis of collagen which ultimately delays healing of wounds, burns and decubitus ulcers.[1] Studies have suggested that Zinc promotes enamel mineralization in post eruption phase and decreases the tooth susceptibility to caries.[1]

Copper

Another vital trace element is Copper, which is a component of various body proteins and enzymes (super oxide dismutase, ferroxidase, cytochrome etc.). This element plays a pivotal role in formation of connective tissue, metabolism of iron, metabolism of cholesterol, functioning of nervous system, immune functions, reducing inflammation. Since copper is not synthesized in body hence its adequate dietary consumption is essential. Any excess copper is normally excreted in bile. Copper deficiency is associated with arthritis, free radical damage, immune dysfunction, inflammatory diseases. Copper deficiency is also associated with iron deficiency which reduces haem synthesis leading to iron deficiency anaemia and infections. The clinical presentation of vitamin C and copper deficiency are similar and at times indistinguishable. [1]

Iron

Iron is used by haemoglobin as a carrier of oxygen to tissues, as a means of transport of electrons by cells and an essential component of enzymes in different tissues. [1] The significance of iron in periodontal health has been widely researched, in a survey conducted by US National Health and Nutrition Examination Survey a modest, yet statistically significant relation was demonstrated between individuals with insufficient iron intake and those with severe periodontal disease, suggesting an association between the prevalence of iron deficiency anaemia, caries, and periodontal diseases within certain populations. [11]

Fluoride

Fluoride is a crucial element that helps to prevent tooth cavities and both iron and zinc act as antioxidants that benefit the periodontium.[1]

Effect Of Malnutrition on Oral Health

A lack of micronutrients in the diet can lead to various insufficiencies. Selective micronutrient deficits can coexist with both undernutrition and obesity. Such deficiencies can result in a person either with appropriate nutritional intake during periods of elevated micronutrient requirements or in state of increased micronutrient loss, as in alcohol misuse and severe smoking.[1]

Several studies have concluded that malnutrition adversely affects dentition in children. It not only delays tooth development but also increases the incidence of dental caries in deciduous dentition. Of the several trace elements researchers postulate that a reduced level of zinc, iron, copper, selenium and strontium are the risk factors for dental caries. Fluoride improves mineralization of tooth and hence recognized as a protective element for the tooth. [1]

Some studies have also established a link between magnesium consumption and dental caries. It is stated that dental abscess exists as a chronic infection without patient’s knowledge and can lead to an elevated copper/iron ratio in blood. [12,13]

It is demonstrated that copper inhibits acid production in dental plaques, caries in rodents and is toxic to streptococcus mutants acidogenoic bacteria. [14]

It has been documented that zinc influences the wound healing in mouth. Zinc concentration in human tooth varies with tooth type, length of root, caries status. Some animal studies suggests that zinc deficiency might be a potential risk factor for oral and periodontal illness. Zinc deficiency has been demonstrated to affect soft surface of molars in young rats and produce dental caries.[1]

Geriatric population with mucosal pathologies has a lower serum iron level as compared to those without it. A higher incidence of malnutrition is also recorded in non-denture wearing complete edentulous patients.[15]

Although a large body of evidence has been recognised suggesting the supporting role of micronutrients in promoting general health but the research suggestive of role of micronutrients on oral health is still in initial stages. Clinicians should opt for a holistic approach towards patient treatment targeted at dietary modification for improving oral as well as overall health of an individual.

1. Shetty P, Shetty A, Kumari S. Micronutrients and oral health an opportunity to prevent oral diseases. Romanian Journal of Diabetes Nutrition and Metabolic Diseases. 2019 Oct 22;26(3):311-6.
   Shetty B, Faruk S, Fazal I , Nambiar M. The impact of micronutrients in periodontal health and disease: A neglected pathway - A review.  Journal of Population Therapeutics & Clinical Pharmacology. 2023; 30 (1): 650-71. DOI:10.2478/rjdnmd-2019-0032

2. Willershausen B, Ross A, Försch M, Willershausen I, Mohaupt P, Callaway A. The influence of micronutrients on oral and general health. European Journal of Medical Research. 2011 Dec; 16: 514-8. DOI: 10.1186/2047-783x-16-11-514

3. Mustafa M, Zarrough A, Bolstad AI, et al. Resolvin D1 protects periodontal ligament. Am J Physiol Cell Physiol. 2013;305(6): C673–C679. doi:10.1152/ajpcell.00242.2012

4. Freeland-Graves JH, Lin P-H. Plasma uptake of manganese as affected by oral loads of manganese, calcium, milk, phosphorus, copper, and zinc. J Am Coll Nutr. 1991;10(1):38–43. doi:10.1080/ 07315724.1991.10718124

5. Staudte H, Sigusch B, Glockmann E. Grapefruit consumption improves vitamin C status in periodontitis patients. Br Dent J. 2005;199(4):213–217. doi:10.1038/sj.bdj.4812613

6. Lee J-H, Shin MS, Kim EJ, Ahn YB, Kim HD. The association of dietary vitamin C intake with periodontitis among Korean adults: results from KNHANES IV. PLoS One. 2017;12(5):e0177074. doi:10.1371/journal.pone.0177074

7. Timmerman MF, Abbas F, Loos BG. Java project on periodontal diseases: the relationship between vitamin C and the severity of periodontitis. J Clin Periodontol. 2007;34(4):299–304. doi:10.1111/ j.1600-051X.2007.01053.x

8. Rathee, Manu & Singla, Shefali & Tamrakar, Amit. (2013). Calcium and Oral Health: A Review. International Journal of Scientific Research. 2. 10.15373/22778179/SEP2013/116.

9. Ghosh, Abhishek & Nagpal, Dr. Bhuvan & Kumar, Vivek & Nayan, Kamal. (2016). Role of Minerals and Trace Elements in Oral Health - A Review. Journal of Oral and Dental Health. 2. 1-2Velliyagounder, Kabilan & Chavan, Krupa & Markowitz, Kenneth. (2024). Iron Deficiency Anemia and Its Impact on Oral Health—A Literature Review. Dentistry Journal. 
   12. 176. 10.3390/dj12060176.

10. MacKeown JM, Cleaton-Jones PE, Fatti P. Caries and micronutrient intake among urban South African children: a cohort study. Community Dent Oral Epidemiol 31(3): 213-20, 2003
    Watts DL. The Nutritional Relationships of Copper. Journal of Orthomolecular Medicine 4(2): 99- 108,1989 DOI: 10.1034/j.1600-0528.2003.00042.x

11. Wu YC, Wang YP, Chang JYF, Cheng SJ, Chen HM, Sun A. Oral manifestations and blood profile in patients with iron deficiency anemia. J Formos Med Assoc 113(2): 83–87,2014. OI: 10.1016/j.jfma.2013.11.010

12. Gupta A, Kapil U. Association of Nutritional and Oral Health Status Amongst Geriatric Population in India (P01-005-19). Curr Dev Nutr 3(Supp 1), 2019. https://doi.org/10.1093/cdn/nzz028.P01-005-19