Recent published research including 41, 504 patient records, revealed a prevalence of 63.6% deficiency of vitamin D with only minor differences by gender and age (Anderson JL, et al. 2010). The researchers found that the vitamin D deficiency was associated with highly significant increases in the prevalence of diabetes, hypertension (high blood pressure) and hyperlipidemia (high cholesterol and triglycerides). The vitamin D levels of the study patients were also highly associated with coronary artery disease, myocardial infarction, heart failure and stroke. Vitamin D deficiencies are very common even in sunny climates because the common use of sunscreen. To spend some time in the sun without sunscreen is healthy as long as you don't overdo it, that is one way to increase vitamin D levels. To get sunburned it not healthy however.
If you want to be sure that you get enough vitamin D, you can also take 1000 IU to 2000 IU of vitamin D3. You can read more about the many benefits of vitamin D by clicking here.