While most Americans get enough vitamin D, certain groups -- such as African Americans and Mexican Americans -- have higher rates of vitamin D deficiency than others, according to the Centers for Disease Control and Prevention. Vitamin D deficiency might cause hair loss and tooth decay, but insufficient amounts of this vitamin aren't always the culprit.
Causes of Hair Loss
Getting too little vitamin D may be associated with hair loss, according to a review published in the June 2009 issue of the "Cleveland Clinical Journal of Medicine." Although the role vitamin D plays in hair loss is not totally understood, a review published in the February 2010 issue of "Dermatology Online Journal" indicates that the vitamin helps start the growth of new hair. Deficiencies in other nutrients -- such as zinc, iron, protein and essential fatty acids -- are also potential causes of thinning hair and hair loss, according to authors of this review. Inherited conditions, some medications, poor hair care, getting too much vitamin A, excessive weight loss and hormonal fluctuations can also cause hair loss.
Vitamin D and Tooth Decay
Getting plenty of vitamin D is important for healthy teeth. Vitamin D deficiency may increase your risk for developing cavities -- or tooth decay -- according to a review published in the February 2013 issue of “Nutrition Reviews.” The review evaluated 24 clinical studies to determine if the vitamin helps prevent cavities and concluded that it was helpful in most cases. Although exactly how vitamin D help maintain healthy teeth isn't clear, it may D help maintain the correct calcium and phosphorus concentrations in the body, two minerals important for strong teeth. But it's still not clear if having low vitamin D levels in your body means you're sure to develop cavities, and more research is still needed to clarify this.
Other Side Effects
The mineral calcium is critical for maintaining strong bones and, because vitamin D helps regulate calcium, a vitamin D deficiency may lead to weak bones and bone pain, according to the Office of Dietary Supplements. The Harvard School of Public Health notes that being deficient in vitamin D may also decrease the activity your immune system and increase your risk of developing heart disease, osteoporosis, cancer, tuberculosis and seasonal flu.
Vitamin D Requirements and Sources
The recommended dietary allowance, or RDA, for vitamin D is 15 micrograms, equivalent to 600 International Units, for adults younger than 70, and 20 micrograms, or 800 International Units, for those over 70. When sunlight strikes your skin, it converts a cholesterol-like substance into active vitamin D, so your body can make all the vitamin D you need if you get 10 to 15 minutes of sun exposure on three days each week. Dietary sources of vitamin D include dairy foods or calcium-fortified soy milk, fish, egg yolks, orange juice and ready-to-eat breakfast cereals. A cup of milk provides about 30 percent of your daily value, 6 ounces of yogurt contain 20 percent and 3 ounces of salmon provide 112 percent of your daily value for vitamin D. Many multivitamin supplements also contain vitamin D.