Bariatric surgery patients tend to have malabsorption of many micronutrients such as B12, Iron and vitamin D postoperative. So in this study, a monthly high dose of vitamin D3 is giving to patients with their routine supplements and followed up for 6 months.

Hypothesis:Bariatric surgery subjects taking monthly high dose cholecalciferol supplements in addition to the standard vitamin D protocol will have a significant rise in serum vitamin D levels compared to the subjects taking only the usual vitamin D protocol.

Sun exposure and supplement use questionnaire:

A registered dietitian asked each subject for information on sun exposure, vitamins, medications, and any other supplement usage before each blood sample was taken.

Lab analysis included serum hydroxy vitamin D levels pre and 3 months postoperative.

Descriptive statistics which include both the means and standard deviations were calculated on the study variables. A paired sample t-test was used to determine if there was a significant difference in mean values pre and post vitamin D supplementation. An independent sample t-test was used to assess for significant differences in group (control vs. vitamin D supplement) means. A p-value < 0.05 was considered statistically significant. Statistical analyses were done using SPSS Version 21 (SPSS, Chicago, III, USA).

Inclusion Criteria:

• morbidly obese and eligible for bariatric surgery

Exclusion Criteria:

• under 18 and over 60 years of age
• elevated serum vitamin D and calcium
• pregnant and lactating women