Micronutrients

Micronutrients consist of vitamins, minerals and trace elements. While micronutrients do not have energy value, they are essential for many biological processes including those that promote periodontal health and/or disease.⁵⁴ Figure 2 summarizes micronutrients associated with oral health.

Figure 2. Micronutrient sources and recommended daily intake.

Figure 2. Micronutrient sources and recommended daily intake.

Vitamin A Complex

Beta-carotene, the naturally occurring pigment responsible for red, orange, and yellow colors in many fruits and vegetables, is a precursor to vitamin A, also known as retinol. Beta-carotene can act as a scavenging antioxidant to destroy free radicals and may also promote increased integrity of epithelial cells and cell-to-cell attachments.⁵⁴ Considering the antioxidant function of beta-carotene, it has been studied to determine the association between periodontitis and beta-carotene with findings suggesting that increased beta-carotene consumption was associated with decreased periodontitis prevalence.⁵⁵ Further, beta carotene has been associated with improved healing in nonsmokers after nonsurgical therapy, including greater reductions in probing depth.⁵⁶ These findings suggest that consumption of beta-carotene may improve antioxidant capacity and may significantly improve periodontal health.⁵⁶ Beta-carotene deficiency is also associated with increased periodontitis prevalence and gingival bleeding.⁵⁶

Vitamin C/Ascorbic acid

Vitamin C has long been known to be associated with gingival health. This association between vitamin C and oral health was first described in the scientific literature in what has been called the first randomized controlled trial.⁵⁷ This study identified a lack of vitamin C consumption as the causative deficiency for scurvy in British sailors.⁵⁷ Scurvy, which is now known to be extreme vitamin C deficiency, was a frequent ailment amongst sailors who lacked access to vitamin C-containing foods during long voyages at sea. Due to scurvy’s association with severe gingival bleeding and tooth mobility, vitamin C deficiency has been postulated to play a role in gingivitis. A well-balanced nutrient-rich 7-day diet that omitted vitamin C, resulted in no changes in plaque index or probing depths but increased bleeding on probing was noted.⁵⁸ It has been established that vitamin C enhances collagen synthesis and protects against tissue damage by scavenging reactive oxygen species (ROS).⁵⁸ Studies have demonstrated an inverse relationship between periodontal disease prevalence and serum vitamin C concentrations and this relationship is more pronounced in individuals with more severe forms of periodontal disease and in never-smokers.⁵⁹ Additionally, consumption of whole food sources of vitamin C (e.g., grapefruit) for two weeks in vitamin C deficient individuals resulted in increased plasma vitamin C levels and improved sulcular bleeding scores.⁵⁹ Vitamin C may also blunt the cytotoxic effects of Porphyromonas gingivalis on human gingival fibroblasts in vitro.^59-61 These findings suggest that dietary vitamin C consumption may play an important role in promoting improved periodontal health and outcomes of periodontal therapy.

Vitamin E

Vitamin E (tocopherol) is a fat-soluble vitamin that has been identified as a key extracellular antioxidant and has been suggested to improve periodontal treatment outcomes.⁶² Dietary sources include: poultry, meat, fish, nuts, seeds, and cereal grains.⁶³ Serum levels of saturated vitamin E, are negatively associated with clinical signs of periodontal disease including: probing depths and overall assessment of periodontal disease severity.⁶⁴ Dietary supplementation with vitamin E results in a reduction of bleeding upon probing and periodontal inflammation.⁶⁵ After nonsurgical periodontal therapy, increased dietary intake of vitamins A, B, C, E combined with with omega-3-fatty acid intake resulted in improved healing in nonsmokers but not in smokers when compared to those who did not take supplements.⁵⁶ These preliminary findings may indicate a role for vitamin E supplementation during the periodontal treatment to enhance periodontal outcomes, particularly in some patient populations.

Vitamin B Complex

The vitamin B complex refers to eight water-soluble vitamins, which together perform functions essential to the body including cell metabolism, repair, and proliferation.³² These vitamins include thiamine (B1), riboflavin (B2), niacin (B3) pantothenic acid (B5), pyridoxine (B6), biotin (B7 or B8), folate (B9), and cobalamin (B12).³² Vitamin B complex deficiencies demonstrate a range of symptoms from dermatititis to paresthesia and include oral manifestations such as angular cheilitis and glossitis.³² Vitamins in the B complex may also play a role in periodontal disease progression and severity. B2, B3, B6, B12 deficiencies have been linked to hemorrhagic gingivitis and periodontitis.⁶⁶ These vitamins support healthy immune functions by strengthening epithelial barriers and cellular and humoral immune responses.⁶⁶ Vitamin B complex supplementation is associated with statistically significantly higher mean clinical attachment gain at shallow and deep periodontal pockets after periodontal therapy.⁶⁷ While heterogeneity exists in clinical investigations, the direct effect of these micronutrients may be influenced by other factors like age and smoking status, which can obscure results.⁶⁷ Additional research to assess the role of the Vitamin B-complex and periodontal health is needed.

Vitamin D and Calcium

Vitamin D is required for a number of essential functions of the human body, including it role in the enhanced resorption of minerals including calcium, magnesium, iron, phosphate and zinc.³² While the role of vitamin D in regulation of plasma calcium and phosphorus levels for bone metabolism has long been established, it is also essential for cell development, neuromuscular functions, and inflammatory system modulation.⁶⁸ Vitamin D has also been found to inhibit pro-inflammatory cytokines and T-lymphocyte proliferation.⁶⁸ Vitamin D is unique among the vitamins discussed in this course in that rather than naturally occurring in dietary sources, sunlight exposure is the most common source of vitamin D.⁶⁸ Vitamin D and Vit-D Receptor complex interact with receptor activator of nuclear factor Kappa-B ligand (RANKL) expression and downregulate osteoprotegerin (OPG), thereby increasing differentiation and activation of osteoclasts and consequently bone resorption.⁶⁸ When vitamin D levels become low, parathyroid hormone indirectly stimulates bone resorption in order to increase vitamin D levels, so increased vitamin D intake may reduce bone resorption.⁶⁸ Despite its role in mineral absorption and metabolism, equivocal study results have not established a definitive association between dietary vitamin D deficiency and periodontal health and/or post-treatment periodontal healing in the general population.³² Local administration, however, of vitamin D has demonstrated enhanced bone turnover in clinical scenarios. For example, dental implants coated with vitamin D3 have demonstrated enhanced osseointegration⁶⁹ and intraperitoneal injections of vitamin D3 have been shown to accelerate orthodontic tooth movement.^70,71

It should be noted that co-supplementation of calcium and vitamin D has demonstrated a positive effect on the outcomes of periodontal therapy⁷² and in two studies of dietary consumpution in a Danish population, higher intake of dairy products high in calcium and vitamin D has been associated with decreaed periodontal disease severity.^73,74

Minerals and Trace Elements

Balanced levels of minerals and trace elements are essential for optimal host immune responses and may preventing progression of chronic conditions such as periodontitis.^32,55 Iron (Fe++) is the most abundant essential trace element with many functions in the human body and is found primarily in blood.⁷⁵ Iron is also required for the synthesis of enzymes and plays a role in the innate and adaptive immune responses.^32,75 The recommended daily allowance for iron varies with age and sex with highest levels recommended for women of reproductive age.⁷⁵ While direct evidence linking iron deficiencies to periodontitis development is scant, inflammation from periodontitis may result in increased pro-inflammatory cytokines, which then may suppress erythropoiesis in bone marrow and lead to periodontal disease progression.^32,76

Other essential trace minerals, including selenium (Se), magnesium (Mg), zinc (Zn), and copper (Cu), have antioxidant enzymes that can aid in neutralizing ROS and prevent tissue damage. They also play important roles in regulating immune function and wound healing.⁷⁷ In particularly vulnerable patient populations, adequate levels of these minerals may be crtically important. For example, zinc has been identified as a potential factor in preventing diabetes-related periodontal disease progression.^78,79 Therefore, achieving ideal levels of these micronutrient minerals may be a critical component in periodontal care.⁷⁷