There are 249 calories in a 3.5 oz serving of Ground beef Ground Beef, crumbled, cooked, drained, rinsed. Calorie breakdown: 57% fat, 0% carbs, 43% protein.here are 249 calories in a 3.5 oz serving of Ground beef Ground Beef, crumbled, cooked, drained, rinsed. Calorie breakdown: 57% fat, 0% carbs, 43% protein.
Sunlight and Vitamin D Synthesis. Exposure to the sunâs ultraviolet (UV) rays is required for vitamin D3 (cholecalciferol) to be produced. Vitamin D3 is synthesized in the skin once your unprotected skin receives exposure to sunlights UV rays. The sun emits three different types of radiation, UVA, UVB and UVC. The ozone layer is good at blocking all of the UVC radiation and most of the UVB, however, none of the UVA radiation.
However, vitamin D can be synthesized by our body when sunlight hits our skin. It is estimated that sensible sun exposure on bare skin for 5-10 minutes 2-3 times per week allows most people to produce sufficient vitamin D, but vitamin D breaks down quite quickly, meaning that stores can run low, especially in winter.