Aim: to investigate the effect of vitamin D3 replacement on body mass index, blood pressure, pulse rate, fasting plasma glucose and serum lipids, in healthy vitamin D deficient adults.
Patients and methods: Twenty-five healthy adult participants (3 males and 22 females) with vitamin D3 deficiency were recruited from the endocrine clinic in a tertiary care hospital in Saudi Arabia. History was taken and clinical examination was done for all participants. Height, weight, sitting blood pressure, and pulse rate were measured. Laboratory investigations in the form of vitamin D3 level, fasting plasma glucose, and lipid profile were measured before the participants received any oral vitamin D3. The same anthropometric and biochemical parameters were measured 9 months after starting vitamin D3 supplementation in the form of oral cholecalciferol. Replacement was given as 4500 units of vitamin D3 drops daily for one month, then 3000 units daily for another month, then 2000 units daily for seven months. This was combined with oral calcium carbonate intake of 500 milligrams daily throughout the nine month study period.
Results: Pretreatment serum vitamin D3 level was 9.01±3.2 nanogram/milliliter. A vitamin D3 level of 35.4±6.84 nanogram/milliliter was achieved by the end of the study. A significant reduction in the pulse rate (p=0.000) and the systolic blood pressure was noticed (p=0.002). The diastolic blood pressure did not significantly change (p=0.148).The rate pressure product (RPP) was significantly reduced by the end of the study (p <0.001). The increase in vitamin D3 level was not associated with significant changes in fasting plasma glucose (p=0.184) or any of the measured components of the lipid profile. There was no significant effect on the body mass index (p=0.31).
Conclusion: Vitamin D3 replacement is associated with a significant reduction of the pulse rate, the systolic blood pressure and the rate pressure product. This indicates a reduction of the cardiac work which may partially explain the cardioprotective effect of vitamin D3. The body mass index does not significantly change with vitamin D replacement . No significant effect of vitamin D replacement on fasting plasma glucose in healthy adults, who are neither diabetic nor prediabetic. Also, no effect of vitamin D replacement on the lipid profile in the same group of healthy population.