The loss of ability to absorb vitamin B 12 (B 12) is the most common cause of adult B 12 deficiency. Impaired absorption of vitamin B 12 may be due to a loss of intrinsic factor or to a number of other conditions that decrease production of gastric acid, which also plays a part in the absorption of B 12 from foods.
One of the best natural insect repellent is Lemon Balm. If you insist to go for organic route, Lemon Balm which contains high Citronellal contents is able to repel insects such as mosquitoes, flies, ants and etc. However, Lemon Balm does not deter butterflies or bees.
Oil of lemon eucalyptus (OLE). This is a natural, plant-based oil. It works as well at preventing mosquito bites as products that contain lower concentrations (6.65%) of DEET. PMD is a version of oil of lemon eucalyptus that is produced in a lab. Repellents containing OLE or PMD may provide up to two hours of protection.