Inclusion Criteria:  Gestation ≤16weeks (16 weeks + 6 days) upon intervention Pre-pregnancy BMI ≥25 kg/m2 Aged 21-45 years Willing and able to provide written, informed consent  Exclusion Criteria:  Having current or past hypo/hyperparathyroidism, hypercalciuria, hypercalcemia or osteomalacia History of renal disease (including kidney stones and etc.), liver dysfunction, tuberculosis or sarcoidosis Pre-existing diabetes mellitus or chronic hypertension Taking lipid-lowering medicine Gestational diabetes (as confirmed by oral glucose tolerance test) or gestational hypertensive disorder Multiple pregnancy