One of the most common nutrient deficiencies in the U.S. is vitamin D. Estimates are one out of every two patients is diagnosed with low levels, and for many, the levels are so low it affects their health.
A decade ago, vitamin D was barely discussed, but today it seems as though it is the “nutrient du jour”—with good reason.
One of four important fat-soluble vitamins, the role of vitamin D in the body is actually more of a steroid hormone than a vitamin.
Most of us know the importance of vitamin D in bone health, but today science has proven this incredible nutrient to have numerous roles in maintaining optimal health.
Vitamin D is needed for our immune health, glucose metabolism and neuromuscular and neurological function. Studies show vitamin D reduces the risk of asthma, cancer, Alzheimer’s, dementia, depression and anxiety. It regulates our inflammatory response and can increase our good (HDL) and decrease our bad (LDL) cholesterol. It also positively influences our sex hormones, giving it the title of the sexiest vitamin!
It is important to understand where we get vitamin D. Contrary to most other nutrients, we get most of our vitamin D from the sun—not from food. A glass of milk is equal to 90 IU’s of vitamin D, whereas just 10 to15 minutes of sun exposure can provide up to 3,000 IU/day! The largest food source of vitamin D is cod liver oil, providing between 600-1000IU per serving. Sadly, it’s not the tastiest of foods and isn’t included in most daily diets.
Since the sun is the main source, it is not shocking that 50 percent of us are deficient. We have three potential strikes against us in absorbing vitamin D. First, most jobs are now indoors, providing little daily exposure to sunshine. Second, if we do venture outdoors, we use sunscreens to prevent skin cancer, which may block the absorption of vitamin D. Lastly, where you live can influence your absorption. Those living north of Atlanta have less than optimal sun exposure for many months of the year.
Another battle for vitamin D is weight. Estimates are that two-thirds of the U.S. population is overweight, and fat cells negatively influence vitamin D levels. Overweight or obese individuals require up to 10 times more sun exposure for skin absorption. Age and the color of our skin also influences absorption, as those older than 65 have difficulty converting the vitamin into its active form, and darker- skinned individuals require more sun exposure to absorb it.
The health of other organs in the body can also impact your levels. The kidneys and liver are responsible for converting vitamin D to its active form. If they are compromised, so are your levels. Inflammatory bowel diseases also negatively influence absorption. If you are supplementing with vitamin D or relying on food sources to boost your levels, the health of your gastrointestinal tract is vital to prevent deficiency.
For those who are not clinically deficient (<30ng/ml), you are not necessarily in the clear. The clinical vs. optimal values of vitamin D are actually quite different. The Vitamin D Council recommends a level greater than 50ng/ml, not 30. With this higher recommendation, estimates of deficiency are closer to 75 percent of the population.
Daily recommendations of vitamin D range between 600-800IU, however, we must remember this is to prevent clinical deficiency, not promote optimal levels. Most physicians agree supplementing between 1,000-5,000IU/day of vitamin D3 is necessary to reach optimal levels.
While risk of toxicity is low, you should visit your doctor to measure your vitamin D level before beginning supplementation.
Be patient; it takes time to raise your vitamin D levels. Work with your doctor to track your progress. You’ll be healthier for the effort!
Jaime Coffey Martinez, MS RD, is a registered clinical and integrative dietitian who practices in the Washington area. She owns Nutrition CPR, LLC — a nutrition consulting company providing one-to-one nutrition coaching and corporate nutrition and wellness programs. Jaime coaches her clients on the importance of choosing real, nutrient-dense foods that will nourish the body, optimize health and help clients achieve their personal goals.