It's long been known that getting too little vitamin D weakens bones. The role vitamin D may play in developing high blood pressure and heart disease is less clear.
Vitamin D deficiency may be linked to heart disease and a higher risk of high blood pressure (hypertension). It's too early to say whether too little vitamin D causes high blood pressure — or whether vitamin D supplements may have any role in the treatment of high blood pressure.
Still, vitamin D remains an important nutrient for overall good health. The Institute of Medicine recommends 600 international units (IU) of vitamin D a day for adults ages 19 to 70. For adults age 71 and older, the recommendation increases to 800 IU a day. Some doctors question whether these levels are adequate and think that getting more vitamin D would benefit many people. However, the Institute of Medicine recommends that adults avoid taking more than 4,000 IUs a day.
If you're concerned that you're getting too little — or too much — vitamin D, contact your doctor. He or she may recommend a blood test to check the level of vitamin D in your blood. Screening for vitamin D deficiency is important in African-Americans and other ethnic groups with dark skin, due to decreased natural production of vitamin D with sun exposure.