Table 1.

Inclusion and exclusion criteria.

Inclusion Criteria

Ages 18–45 years Sexes: males and females Females not of childbearing potential (i.e., hysterectomy, oophorectomy, bilateral tubal ligation, or postmenopausal) or females of childbearing potential that agree to use a medically approved method of birth control such as hormonal contraceptives, double-barrier, non-hormonal intrauterine devices, or non-heterosexual lifestyle or agree to use contraception if planning on changing to heterosexual partner(s) and/or vasectomy of partner BMI 18.5 to 29.9 kg/m2 Agree to maintain current level of physical activity throughout the study Agree to wear sunblock of at least SPF 45 during the study and not to have excessive sun exposure (no more than 1 h without sunblock)

Exclusion Criteria

Women who are pregnant, to be determined by UPT (urine pregnancy test), breastfeeding, or planning to become pregnant during the course of the study Duodenal ulcer or gastric ulcer, gastritis, hiatus hernia, or GERD within the past 3 months Significant gastrointestinal disease, history of malabsorption, or history of irritable bowel syndrome and related disorders Unstable medical conditions as determined by the principal investigator Clinically significant abnormal laboratory results on CBC or BMP at screening Cancer chemotherapy/radiation treatment within the 3 months prior to enrollment Metabolic disease History of kidney stones Use of prescription or over the counter products known to interact with vitamin D within 72 h of randomization and during the trial such as aspirin and NSAIDs, aluminum, iron, and proton pump inhibitors Use of acute over the counter medication within 72 h of test product dosing Smokers Consumption of more than 2 alcoholic drinks per day Drug abuse within the past year Use of medicinal marijuana Immunocompromised individuals such as individuals that have undergone organ transplantation or individuals diagnosed with human immunodeficiency virus (HIV) Individuals who have planned surgery during the course of the trial Use of St. John’s wort in the last 30 days before randomization and during the study Use of vitamin D, multivitamins containing vitamin D, foods or beverages fortified with vitamin D and other natural healthy products containing vitamin D, or consumption of grapefruit/grapefruit juice within 14 days of randomization and during the study Use of anticoagulants, barbiturates, tetracycline antibiotics, beta-blockers, cyclosporine, prednisone, tricyclic antidepressants, diuretics, and nitrate medications History of blood/bleeding disorders Anemia of any etiology defined as hemoglobin < 14.0 mg/dL for males and < 12.3 mg/dL for females Blood donation in the past 3 months, or individuals planning to donate blood during the study or within 30 days of completion of study Participation in a clinical research trial within 30 days prior to randomization Allergy or sensitivity to any ingredient in supplements provided during the study Individuals who are cognitively impaired and/or who are unable to give informed consent