Economic history of the United Kingdom diets with nutritional deficiency. The lack of vegetables and fruits in their diets caused a deficiency in vitamin C, sometimes resulting in scurvy. Trade and industry flourished in the 16th century, making England more prosperous and improving the standard of living of the upper and middle classes. However, the lower classes did not benefit much and did not always have enough food. As the English population was fed by its own agricultural produce, a series of bad harvests in the 1590s caused widespread distress. In the 17th century the food supply improved. England had no food crises from 1650 to
Vitamin D and neurology vitamin D blood concentration standard for diagnosing hypovitaminosis D does not exist. In the past, hypovitaminosis D has been defined by blood concentrations lower than 20 ng/ mL. However, in more recent literature many researchers have considered 30 ng/ mL to be an insufficient concentration of vitamin D. Subnormal levels of vitamin D are usually caused by poor nutrition or a lack of sun exposure. Risk factors for hypovitaminosis D include premature birth, darker skin pigmentation, obesity, malabsorption, and older age. The brain requires the use of many neurosteroids to develop and function properly. These molecules are often identified as