The simple view of the bonding in methane You will be familiar with drawing methane using dots and crosses diagrams, but it is worth looking at its structure a bit more closely. There is a serious mis-match between this structure and the modern electronic structure of carbon, 1s 2 2s 2 2p x 1 2p y 1.
Lack of sun exposure: Lack of sun exposure is a major cause of low vitamin d level especially if you live in the northern us. Less likely would be lack of vitamin d in food, but also a possibility if you are on a very restrictive diet.
Not due to low D: It's not likely to be due to low vitamin d. Vitamin d is insufficient if below 30ng/ml and deficient if below 20ng/ml. Even in these situations it shouldn't be slowing your heart rate. More likely it may be related to mineral deficiency. ...Read more.