Vitamin D Deficiency
Why do Americans living in the South have lower rates of certain cancers than those living in the North? According to Consumer Reports on Health, higher vitamin D levels, achieved through greater sun exposure, may have protective effects against cancer. Current studies reported in Nutrition Action Health Newsletter also link low vitamin D levels to increased risks of diabetes, insulin resistance, muscle weakness, gum disease, multiple sclerosis, arthritis, osteoporosis, joint pain, and heart disease.
According to the Harvard Health Letter, some experts claim that the current RDA (recommended daily allowance) of 400 IU (International Units) of vitamin D is low, and that adolescents, adults, and seniors should aim for 800-1000 IU per day. Good food sources of vitamin D are extremely limited, with fish (salmon, sardines, bluefish, and mackerel) the only high sources of natural vitamin D. This makes it virtually impossible, particularly for Northerners, to get optimum vitamin D levels without supplementing.
You can get some idea of your intake by calculating vitamin D amounts in supplements and fortified foods. Keep in mind that there are two types of vitamin D; D3 (cholecalciferol) is better absorbed and found in better quality supplements, whereas D2 (ergocalciferol) does not get absorbed by the body as well. Due to the general public’s lack of knowledge about vitamin D, it is highly advisable to have your physician check your vitamin D level and give you some guidelines for safe sun exposure and proper nutritional supplementation.