Table 1 Eligibility criteria for the feasibility trial

To be included women had to:

Women were excluded if they:

 Be aged ≥18 years at the time of recruitment

 Had a positive diagnosis of HIV/AIDS, syphilis, psychosis, diabetes before or during pregnancy, thyroid disease or any disorder causing vitamin D hypersensitivity (e.g. sarcoidosis and other lymphomatous disorders)

 Be up to 20 weeks’ gestation at 1st prenatal visit

 Had lactose intolerance, milk allergy, history of kidney stones or family history of kidney stones or hyperparathyroidism

 Have a positive diagnosis of periodontitis (≥ 1 tooth with at least one site with equal or more than 4 mm of clinical attachment loss [CAL] and presence of bleeding on probing); and

 Were being prescribed or using antibiotics or any immune suppressants or medication affecting vitamin D/calcium metabolism or had drug or alcohol abuse

 Be cognitively and physically able to complete an interview and oral examination and willing to participate, including providing blood samples

 Reported consumption of equal or more than 4 servings per day of dairy products or taking vitamin D supplements more than 400 IU/day

 Had extensive dental decay (crowns of several teeth destroyed by caries) or use of fixed dental braces