Hello there ,
If you are on a vegan diet , you can have any fermented food - like dosa, edli, dhokla , last night chapati . These foods contain a good amount of
Vitamin B12. But only based on the level of deficiency,I can advise you on the quantity of food or whether you need to go for a B12 supplement.
Secondly for
Vitamin D , you should be going for weekly supplements. The supplement of Vitamin D has to be taken with lunch - once a week ( again dosage I can accurately say after seeing your blood report of Vitamin D) .
Thirdly Omega -3 ,you can get from adding flax seed (roasted) , soaked walnuts , almonds or by using rice bran oil in cooking .
Omega 3 is very useful for muscle building, lubrication of joint and vitamin D absorption.
The fourth point is about
Calcium ,Iron and Zinc ; all three are minerals which you can easily get from leafy vegetables,nuts and dates (iron) .
All together,taking care of your quality sleep , managing your stress , doing 150 min physical activity per week and drinking enough water (2-3L) and taking a diet - containing protein, carbs , fats and vitamins - minerals. Will help in body building and fat loss.