Perryman Nutrition Column: Vitamin D Not Just for Bones Anymore

Note to Editors: The following column was written by Shirley Perryman, a registered dietitian and Extension specialist at Colorado State University’s Department of Food Science and Human Nutrition, College of Applied Human Sciences.

Vitamin D is promoted as essential for bone health because it plays a pivotal role in adequate absorption of calcium and phosphorus to build bone. It also helps us avoid the risk of osteoporosis and fractures.  

Recent studies show that vitamin D is critical to cardiovascular health. Too little increases your risk factors for heart disease including hypertension, diabetes, obesity and high triglycerides. It may also be linked to the risk for autoimmune diseases, certain cancers, infections, depression and mortality.  

Though more studies are needed to determine the extent of vitamin D’s health benefits, the latest evidence strongly suggests that it’s important to get adequate vitamin D. Current recommendations for vitamin D up to age 50 are 200 IU, 400 IU between the ages of 51 and 70, and 600 IU after age 70.  These amounts are based on the need for vitamin D to prevent bone disease.  Some experts now suggest optimal intakes should be higher with at least 1,000 IU recommended for healthy adults.

Living in Colorado allows us to enjoy nearly 300 sunny days a year, but summer is over and exposure to the sun’s rays from November to March will be more limited.  The amount of vitamin D, often called the "sunshine vitamin," our skin will make is determined by exposure to the sun related to the time of day, season, latitude where we live, and our age and skin color.  We are advised to protect ourselves from skin cancer outdoors by using sunscreen and we wear more clothes in colder weather further minimizing our contact with the sun. Other factors that affect sun exposure are the amount of cloud cover and haziness.  The critical ultraviolet B or UVB light does not travel through glass, minimizing our skin’s access to vitamin D when sitting in an indoor sunny spot.  Those with darker skin and the elderly make less vitamin D from sun exposure.  Individuals with cystic fibrosis, inflammatory bowel disease, and certain liver and kidney diseases, may be unable to absorb vitamin D regardless of how much is consumed.

Aim first to get vitamin D from dietary sources though getting adequate vitamin D naturally from food can be challenging even for the most nutrition conscious individual:

– Drink an eight ounce glass of fortified cow’s milk, soy milk, rice milk or orange juice for 100 IU of vitamin D.

– Not all dairy or soy products are fortified with vitamin D. Check the labels of yogurt, cheese and tofu for added vitamin D.

– Certain cereals and breads are also fortified with vitamin D and can provide as much as 100 IU per serving.

– Other rich sources are fatty fish such as salmon and tuna, and smaller amounts can be found in egg yolks. Though vitamin D is found in some plant foods, it’s not absorbed well.

– Supplements can help you meet the recommended level of vitamin D of 800 to 1000 IU if the sun is not a reliable source or your diet lacks the better sources of this vitamin.

Be particularly vigilant of your intake if you’re over the age of 50.  Keep in mind the recommended daily intake according to your age and avoid taking more than 2000 IU as excess amounts of this fat soluble vitamin may be toxic. If you take supplements, count the total the amount of vitamin D from all supplement sources.  If you feel your health merits a check with your physician, a blood test for vitamin D can be done.

The American Heart Association recommends healthy people get adequate vitamin D by eating a variety of foods in moderation rather than by taking supplements. Certainly supplements aren’t a substitute for consuming a balanced diet and shouldn’t be the first line of defense.

Take a self-inventory of your own diet, and make the best choices to ensure you are getting adequate vitamin D for strong bones and a strong heart.