Vitamin D has become the recent darling of health gurus and rightfully so based on a lot of new research.  Vitamin D is found in foods and is also made in your body after exposure to ultraviolet (UV) rays from the sun.  While various forms of the vitamin exist, calciferol is the most active form that our bodies use.     

We know it is a vitamin, but did you know that vitamin D is also a hormone?  Active vitamin D functions as a hormone because it sends a message to the intestines to increase the absorption of calcium and phosphorus.  While various forms of the vitamin exist, calciferol is the most active form that our bodies use. 

The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus.  By promoting calcium absorption, vitamin D helps to form and maintain strong bones. Vitamin D also works in concert with a number of other vitamins, minerals, and hormones to promote bone mineralization. Without vitamin D, bones can become thin, brittle, or misshapen.

Research also suggests that vitamin D may help maintain a healthy immune system and help regulate cell growth and differentiation which is the process that determines what a cell is to become.  Now scientists are finding that it helps prevent numerous chronic conditions, such as cardiovascular disease, autoimmunity, and cancer.  Amazingly, it is estimated that 1 billion people worldwide are deficient in the vitamin.   

In Dr. Andrew Weil’s February 2008 “Self Healing” newsletter, he described five more reasons for taking the supplement.  

Aging:  People older than 60 make only one-third of the amount of vitamin D from sun exposure as they did in their 20s (throw in our usual load of overcast days and that makes us get even less at any age).  Low levels of the vitamin have been associated with poorer cognitive function.  Those ‘senior’ moments might just be related to Vitamin D deficiency.  One recent study found that adequate amounts were linked to a blood marker that indicated lower levels of inflammation and stress.  Dr. Weil indicated he’s been taking 1000 IU of vitamin D3 every day for years and recommended the same for his readers.   This amount is well under the tolerable upper intake level recommended by The Food and Nutrition Board of the Institute of Medicine. 

Osteoarthritis:  A deficiency of the vitamin has been found to increase pain and disability in people with osteoarthritis in their knees and makes the disease progress faster in general.  Osteoarthritis is the form caused by wear and tear on the body.   

Diabetes:  Higher levels of Vitamin D was found to lower the risk of developing type 2 diabetes and previous research has suggested that giving children the supplement significantly reduces their risk of type-1 diabetes. 

Cancer:  Dr. Weil’s article stated that hundreds of thousands of cancer cases worldwide could be prevented each year if people raised their Vitamin D levels, especially in colder climates where breast, prostate, colon, and ovarian cancers are higher and levels of the vitamin are lower.  A study of more than 1000 postmenopausal women in Nebraska concluded that those taking 1100 IU of Vitamin D daily had a 60-77% lower incidence of cancer than women taking a placebo.  And lab experiments have found the vitamin stops cancer cells from growing and spreading.  This is indeed very exciting news.  

Infection:  Since the vitamin has been found to increase the body’s ability to attack bacteria, fungi, and viruses, raising the level may help prevent or minimize infections.

Oddly, even though our bodies make Vitamin D from ultraviolet rays, people living in areas with lots of sun don’t always make sufficient amounts without taking supplements.  However, before you book that cruise to the Caribbean to stock up on Vitamin D, realize that the body’s production reaches its highest level after about 15 minutes of sun exposure.  Any more than that and you risk skin damage and get no added value for all your efforts.  

Vitamin D deficient diets are associated with milk allergy, lactose intolerance, bowel disease, and strict vegetarianism.  One more thing to keep in mind is that factors like dark skin, obesity, heredity, and taking certain medications such as steroids and antacids may decrease the body’s ability to make Vitamin D.   

Infants fed only breast milk also receive insufficient amounts of vitamin D unless they also receive appropriate levels of vitamin D supplementation.  Prolonged exclusive breastfeeding without vitamin D supplementation is one of the most significant causes of the reemergence of rickets, a disease causing bone deformities.  Additional causes include extensive use of sunscreens and increased use of day-care, resulting in decreased outdoor activity and sun exposure among children.

Since a deficiency of the vitamin doesn’t have any obvious symptoms, some experts are now suggesting that everyone get a blood test (for serum 25-hydroxy vitamin D) at least once in their life time to determine their level.  Talk to your health provider if you have questions.   

In Health,
Janet Wildeboor, RN, MS
Health Ministries Committee