Table 4.

Study outcomes.

Study Number	Vitamin D Assessment	Outcomes	Risk Factors
Alvim-Pereira et al. [21]	NR	9.8% implant loss rate	No association between Vitamin D TaqI receptor polymorphism and implant loss.
Flanagan et al. [22]	Vitamin D3 supplementation, phosphate binders and calcium cinacalcet calcimimetic, 3 × dialysis/week	Successful implantation	Low serum Vitamin D levels do not pose an elevated risk for loss of dental implant if calcium levels are properly corrected in patients with IgA nephropathy.
Bryce et al. [23]	Severe Vitamin D deficiency	Successful implantation	Low serum Vitamin D might contribute to unsuccessful osseointegration in dental implants.
Fretwurst et al. [24]	Vitamin D deficiency	22.2% implant loss rate	Successful replacement after Vitamin D supplementation
Mangano et al. [25]	Vitamin D deficiency in 53.7% of patients; 29.5 ng/mL vs. 25.4 ng/mL in the early failure group	3.9% implant loss rate; 11.1% among patients with severe vitamin D deficiency	Four times higher prevalence of early implant loss with low serum Vitamin D levels; higher when associated with smoking and periodontal disease.
Pereira et al. [26]	Vitamin D deficiency due to receptor mutation	11.4% implant loss rate	Vitamin D allele G of rs3782905 significantly associated with poor osseointegration.
Kwiatek et al. [27]	Day of surgery: 23.9 ng/mL, After 6 weeks: 30.4 ng/mL, After 12 weeks: 33.1 ng/mL	NR	Significantly higher bone density in patients with Vitamin D supplementation after 12 weeks.

NR—not reported; OR—odds ratio. Vitamin D hypovitaminosis (insufficiency) is considered below 20 ng/mL or 50 nmol/L; vitamin D deficiency is considered below 10 ng/mL or 25–30 nmol/L; severe deficiency is considered for levels below 10 nmol/L.