Although levels above 30 ng/mL are considered optimal for bone metabolism, only 10 percent of the study sample had levels in this range, researchers said. 120 participants developed a first cardiovascular event including fatal and nonfatal coronary heart disease; 28 participants had fatal or nonfatal cerebrovascular events such as nonhemorrhagic stroke; 19 participants were diagnosed with heart failure; and 8 had occurrences of claudication, fatigue in the legs during activity. "Low levels of vitamin D are highly prevalent in the United States, especially in areas without much sunshine ... Twenty to 30 percent of the population in many areas has moderate to severe vitamin D deficiency." Most of this is attributed to lack of sun exposure, pigmented skin that prevents penetration of the sun's rays and inadequate dietary intake of vitamin D enriched foods, researchers said. Full Article at Science Daily