Can supplementing the diet with vitamin D prevent the development of certain chronic diseases? Researchers have known for many years that vitamin D intake promotes good bone health by helping our bodies to absorb calcium, but they are now thinking that it may help protect against developing diabetes, cancer, heart disease and metabolic syndrome (high blood cholesterol and triglycerides, high blood glucose, increased waist size and high blood pressure) which is a risk factor in developing type 2 diabetes.  In addition, research suggests that vitamin D intake helps maintain a healthy immune system.

Vitamin D is a fat-soluble vitamin that is not found naturally in many foods.  The best sources of vitamin D in the diet are fatty fish (salmon/trout), egg yolks, beef liver, cod liver oil and foods that are fortified with vitamin D (milk and some orange juices).  Signs of deficiency of vitamin D in the body are rickets (bone deformation in children); soft fragile bones; enlarged joints; bowed legs; chest, spinal and pelvic bone deformities; convulsions; osteomalacia (softening of bones in adults).  On the flip side, too much vitamin D (more than 10,000 IU/day) is considered toxic.

Luckily, the body does not need dietary sources of vitamin D to achieve sufficient levels in the blood stream.  The body can make adequate amounts of vitamin D by utilizing sunlight’s ultraviolet beta (UVB) rays to covert an inactive form of vitamin D into the active, usable form. The inactive form of vitamin D comes from cholesterol produced by the liver and is transformed in the kidneys into the active form with help from the sun’s UVB rays.

Now, I’m not saying that you should go sit in the sun all day long or hit the tanning bed.  UVB rays are the same rays that cause sunburn and skin damage, so exposure should be limited.  The body can make adequate amounts of vitamin D from limited sun exposure – 5 to 15 minutes in the sun without sun screen 2 to 3 times per week.

Because of the benefits of vitamin D intake, the recommended dietary allowance (RDA) of vitamin D has been increased for all age groups.  The new guidelines are as follows:

• Infants – 12 months: 400 IU/day
• 1 year – 70 years: 600 IU/day
• 71+ years: 800 IU/day

When available, choose a supplement of vitamin D3 (cholecalciferol) over vitamin D2 (ergocalciferol) to protect bone health. Read dietary supplement labels to help you make the best choice.  If you avoid milk products, ask your physician about taking calcium and/or vitamin D3 supplements.  The take-home message for vitamin D intake is as follows:   Increase time spent outdoors in the sunlight and consume more foods high in vitamin D to obtain the health benefits of adequate vitamin D intake.