This weekend we move the clocks forward and get more precious hours of daylight after a long dark winter. It also marks the day I normally cut back on my vitamin D supplements. I started taking them a few years back, when I noticed that the dark winter months impacted my mood and overall wellbeing. But last April, when I went in for my annual physical, my physician told me that my blood work showed that I literally had no stores of vitamin D in my system—even though I was still taking vitamin D supplements daily.
I am not alone. Donald Hensrud, MD, medical director of the Mayo Clinic Healthy Living Program says, at least 20-50 percent of adults have some form of low vitamin D values. "Low vitamin D is more common in winter months, because of less sunlight, but it is more common in African-Americans because they convert less vitamin D from one form to another in the skin," Dr. Hensrud says. According to Dr. Hensrud, vitamin D deficiencies are also more common in obese individuals and for people with kidney or liver disease. High rates of overweight and obesity, as well as high rates of diabetes related kidney disease can put African Americans at even higher risk.
A study in the Journal of the American Medical Association also suggest that being over age 65 puts individuals at greater risk for being vitamin D deficient. The same study reports that there is an increased risk of dementia and cognitive impairment among seniors who have low levels of vitamin D.
So how do you know if you are suffering from a vitamin D deficiency? According to Dr. Hensrud, "there are no guidelines to routinely test a blood level of vitamin D (the correct test is serum 25(OH) vitamin D or 25 hydroxy vitamin D). If someone has risk factors for vitamin D deficiency or has osteoporosis it may be worth considering checking levels through a routine blood test through their health care provider.
According to Dr. Hensrud, the impacts are significant enough they should not be ignored. "While there are some symptoms that can occur, such as muscle weakness and joint pain, depression and heavy sweating with just normal exertion," Dr. Hensrud says. "We now know that vitamin D is involved in much more in the body than bone disease. It is linked to immune function, muscle function and the risk of falls, cancer prevention, chronic pain, various cardiovascular risk factors, and possibly other conditions."
Part of the problem is inconsistent messages on how much vitamin D we need to maintain our health and wellness. In 2010, the Institutes of Medicine set standard guidelines for a healthy daily amount of vitamin D for the average adult at 600 International Units (IU). Later, other studies suggested that the amount of vitamin D that an individual needs is somewhere between 6,000 and 8,000 IUs. That's a significant gap.
While it was once thought that we can boost our levels through eating foods that contain vitamin D and getting enough sunlight exposure, it might not be enough. Dr. Henstrud, says "you can increase your levels of vitamin D, but it is very difficult to come back from a deficiency through enriched foods such as fatty fish, cheese, liver, eggs, fortified foods like cereal and milk alone. "
According to Dr. Hensrud, " vitamin D deficiency almost always requires supplements. The amount of supplementation depends on how severe the deficiency." He says "there ere are also different regimens to take it ranging from 1,000 units per day for mildly low levels up to 50,000 units weekly for a few weeks to replace severe deficiency."
"Multivitamins vary in how much vitamin D they provide, but more of them are providing the RDA of 600 units or even a little more such as 1,000 units, " Dr. Hensrud says. "Some vitamin D experts, such as The Endocrine Society, recommend that people take 1,500 - 2,000 units daily and many physicians are recommending similar amounts. " He adds that some people choose to take a separate vitamin D supplement for this reason.
Addressing a severe deficiency should be done under the supervision of your physician. Dr. Hensrud cautions that "large amounts vitamin D can be toxic and cause problems with high calcium levels in the blood and urine which can lead to other symptoms and health problems." The Institute of Medicine states people should not take more than 4,000 units daily, but many experts put the maximum amount at 10,000 units.
So what should you do? Dr. Hensrud says that if you are concerned about your vitamin D levels, get a blood test from your provider as a part of your routine blood work. But he adds that since the tests can be expensive for those not covered by insurance, a hack could be to start by taking vitamin D supplements can cost less than $10-$20 for a 3 month supply of vitamin D3, 2,000 units. Just by taking this preventative step you could be raising your vitamin D levels on your own, under the supervision of your doctor.