Part of the secret to strong bones is to have enough vitamin D in your blood. Ergocalciferol, or vitamin D-2, and cholecalciferol, or vitamin D-3, are two types of vitamin D that are essential to humans, the University of Maryland Medical Center explains. Vitamin D-2 is the type made by plants, and vitamin D-3 is the type produced by your skin after exposure to sunlight. Vitamin D is also helps regulate your immune system and helps lower your risk of cancer.
Determining the amount of vitamin D in your body is done through a blood test called the 25-hydroxy vitamin D test, according to National Institutes of Health online medical encyclopedia Medline Plus. The test requires a four-hour fasting period. Most doctors consider the normal range for vitamin D in your body to be between 30 ng/ml to 74 ng/ml. However, you actually need between 50 ng/ml to 80 ng/ml for optimum health, VitaminDCouncil.org explains.
Adequate intake levels of vitamin D and D-2 vary according to age. The recommended dose for people under the age of 50 is about 5 mcg daily, MayoClinic.com explains. Adults between the ages of 50 to 70 need 10 mcg each day. Adults older than 70 need 15 mcg of vitamin D to stay healthy. People under the age of 50 who live in environments with little sunlight require as much as 10 mcg each day.
Vitamin D deficiency has been linked with rickets, or weak bones in children, the University of Maryland Medical Center explains. Having insufficient vitamin D levels increases your risk of developing diseases such as cancer, high blood pressure and obesity. Insufficient vitamin D also elevates your risk of developing problems with your parathyroid hormone production. Other conditions linked with low levels of vitamin D include diabetes, multiple sclerosis, heart disease and seasonal affective disorder.
Side Effects and Possible Interactions
Too much vitamin D causes health problems such as hypercalcemia and kidney stones, Medline Plus notes. Hypercalcemia occurs when your intestines absorb too much calcium and sometimes causes calcium deposits to form in your heart and lungs, which can impair their function. Too much vitamin D also causes fatigue, sleepiness and appetite loss. Vitamin D also interacts with medications such as atorvastatin, calcipotriene and water pills.
Dietary Sources and the Sun
Vitamin D is available in dairy products that have been fortified with it, such as cheese, butter and cream. Other food sources for vitamin D include fatty fish such as salmon, tuna and mackerel as well as cod liver oil. Eggs also contain vitamin D. Sun exposure is also another way to get vitamin D. Fair-skinned people need weekly sun exposure of about 45 minutes to get their recommended vitamin D requirement. People with darker skin need as much as three hours of exposure to get the same amount of vitamin D.