To prevent this, use the smallest gauge needle practical for drawing doses (29-31 gauge insulin needles), always insert the needle straight (not at an angle), and try to puncture the same spot on the stopper each time rather than creating new holes across the surface
Cancer Cell 2010;17:225-34
To increase the amount of vitamin B12 in your diet, eat more foods that contain it, such as: Beef, liver, and chicken Fish and shellfish such as trout, salmon, tuna, and clams Fortified breakfast cereal Low-fat milk, yogurt, and cheese Eggs Your doctor might recommend that you also take a vitamin B12 supplement
Sources: Yang, Xi-Ding, and Yong-Yu Yang