Hi welcome - I advise you to take methylcobalmine tab/ cap as nutritional supplements ,also add some digestible or tolerable dairy sources like chana,, sour tasted curd,yoghurt, &
vitamin d3 mostly available in seafoods & cod
liver oil, shark liver oil etc. Even you get like pomfret, flat belly fish.. Take all limited but compulsorily as these are the best sources for you. Also sunlight in winter season can produce d3.