Vitamin D as a supplement is found to be helpful in battling with viral infections including covid 19. It is known also that most people are Vitamin D deficient. The recommended daily allowance is 600 international units (IUs). A private study revealed the following analysis. Two-Sample T-Test and CI: vitD vs. gender : mean vitD when gender= females : mean vitD when gender = males Difference: - vitD gender N Mean StDev SE Mean females 64 604 86.8 10.85 males 49 584 79.2 11.32 Estimation for Difference Difference 95% CI for Difference 20 (-10.73, 50.74) Test Null hypothesis 0 H 0 : 12=0 1 2 = 0 Alternative hypothesis 1 H 1 : 120 1 2 0 Z-Value P-Value 1.28 ------ Options: we can reject or not reject P value is <.001, .057, 0.013 or .200 Vit D for females is 433.872,774.128 -10.73,50.74 or 607.919,625.266 and is either greater than,equal to, cannot be compared with or less than Two means differ or do not differ