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.
The second reason for a low vitamin D is that you have primary hyperparathyroidism due to a small tumor in your neck and the body converts all the vitamin D-25 (that your doctor is measuring) to the active Vitamin D-1-25 (that doctors do not measure). This is the blue blob on the graph.
Not many foods contain vitamin D, and vitamin D added to foods is not well regulated. In addition, even eating foods with added vitamin D may not give you enough of the vitamin for optimum health. The two most common causes of low vitamin D levels are lack of sun and not enough intake of vitamin D by mouth. Other causes of low vitamin D levels include the bodyâs inability to absorb enough vitamin D (intestines made shorter by surgery, gastric bypass, and intestinal diseases), chronic kidney disease, and liver failure (Table 1).