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.
PMD is the ingredient in the oil that makes it repellent to insects. When researchers from New Mexico State University tested a variety of commercial products for their ability to repel mosquitoes, they found that a product containing lemon eucalyptus oil was about as effective and as long lasting as products containing DEET.