Vitamin D Deficiency: Are You At Risk?
As the days get shorter and the weather grows colder, your daily dose of vitamin D - also known as the sunshine vitamin - is decreasing. If you don't usually spend much time outside and don't get enough of vitamin D in your diet, your body may already be deficient. In the past, a vitamin D deficiency was generally thought of with regard to rickets, a condition mainly affecting children which produces soft, weakened bones, resulting in skeletal deformities. Thanks to continuing research in this area, it is now known that vitamin D is essential not only for good bone health, but also for the health of your immune system. Even if you get enough vitamin D from your diet or take supplements, your body may not be able to benefit from it if you have digestive problems or a defect in any of the several genes which regulate vitamin D metabolism.
Vitamin D: Not Just for Healthy Bones
Vitamin D is actually a hormone that plays an essential role in the body's absorption and use of calcium in order to grow, strengthen, and maintain healthy bones. It's also necessary for proper muscle function as well as for a healthy immune system. Recent research links cancer (breast, colorectal and prostate), heart disease, diabetes, and multiple sclerosis to low levels of vitamin D.1,2 In addition, vitamin D deficiency is increasingly being associated with other health problems like asthma, infections, depression, and even obesity.3,6 While more research is needed to clarify the exact role vitamin D plays in these diseases, its importance in maintaining good health cannot be overstated.
Getting all the benefits from vitamin D is dependent on several factors working together. If one of them is not functioning correctly, your body may not be able to absorb or utilize vitamin D. Here's a quick look at what is involved:
Sun Exposure: The sun is the most plentiful source of vitamin D as your skin is able to efficiently produce it when you spend time in the sun. Due to a rise in the amount of skin cancer, however, we've reduced our exposure to the sun by either avoiding it, wearing protective clothing or using sunscreen. A recent study out of Denmark found lower vitamin D levels in individuals who frequently sought shade or wore protective clothing.4 Here, exposure to sun was found to be the most important determinant in the level of vitamin D when compared to the role of genes and dietary intake.
Diet: Certain fatty fishes such as mackerel, salmon, and herring as well as fish oils like cod liver oil are rich in vitamin D. Vitamin D requires fat for it to be absorbed from your gut, so diets low in fat or medications that block fat absorption can limit how much vitamin D your body actually gets. Since most of us don't get enough vitamin D in our diets, it's been added to products like milk, orange juice, yogurt, cheese, and bread. Even then, some people still don't get enough vitamin D - making supplements an important part of maintaining your health.
Supplements: Here, moderation is important as excessive amounts of vitamin D are associated with health risks. The minimum recommended dose of vitamin D for adults is 800 IU, but many people may need more as sunscreens with SPF higher than 8 prevent absorption of vitamin D from the sun. 5
A Healthy Digestive Tract: If you aren't getting enough vitamin D from the sun, your body is dependent upon the vitamin D you consume, either from your diet or in the form of supplements. Digestive issues, food allergies or illnesses like celiac disease and Crohn's disease can impair your ability to absorb vitamin D.
Your Genes: Vitamin D absorption and metabolism are complex processes which are regulated by several genes. Abnormalities in any of these genes or defects in the intracellular vitamin D receptor can affect your levels of vitamin D and calcium, putting you at risk for many different health problems.3 Genetic testing enables your healthcare practitioner to identify if you are at greater of risk vitamin D deficiency and take action.
Additional factors that can negatively affect your vitamin D levels include:
Medications: Certain medications such as steroids or anti-seizure medications can interfere with your body's use of vitamin D.
Age: Your skin produces less vitamin D as you age.
Are You Low in Vitamin D?
Sensible sunbathing (see our blog on being smart about the sun) and adequate dietary intake of vitamin D are essential first steps to improving and maintaining your level of vitamin D. The most important thing you should do, however, is to have your healthcare practitioner test you to see if you are low in vitamin D. Once you know your vitamin D status, your healthcare practitioner can recommend appropriate doses of supplemental vitamin D.
Make sure you choose a supplement that provides you with vitamin D3 - the form which your body can most easily use.
Raising your vitamin D status to optimal levels can take up to 6 to 10 months. and re-testing is recommended to check that your body has successfully replenished its stores of vitamin D. Depending upon your health status and your level of vitamin D, your healthcare practitioner may also recommend genetic testing to determine if you could have any genetic abnormalities that may be affecting your ability to attain healthy levels of vitamin D.
If you would like more information on vitamin D deficiency or if you think you could be low in vitamin D, please contact us today. For information on the Metagenics line of high quality vitamin D3 supplements, check out our e-store.
1 Jacobs, ET et al. Vitamin D and Colorectal, Breast, and Prostate Cancers: A Review of the Epidemiological Evidence. J Cancer. 2016 Jan 5;7(3):232-40.
2 Lips, P. Abstract: Vitamin D Physiology. Prog Biophys Mol Biol. 2006 Sep;92(1):4-8.
3 Arash, H-N, Holick, M. Vitamin D for Health: A Global Perspective. Mayo Clinic Proc.2013 Jul. 88(7): 720-755.
4 Hansen, L et al. Sun Exposure Guidelines and Serum Vitamin D Status in Denmark: The StatusD Study. Nutrients. 2016 May; 8(5): 266.
5 Brouwer-Bulsama, EM, et al. Abstract: Relative importance of summer sun exposure, vitamin D intake, and genes to vitamin D status in Dutch older adults: The B-PROOF study. J Steroid Biochem Mol Biol. 2015 Aug 11. pii: S0960-0760(15)30045-5.
6 Abbas, MA. Physiological functions of Vitamin D in adipose tissue.J Steroid Biochem Mol Biol. 2016 Aug 9. pii: S0960-0760(16)30219-9.
The contents of this blog are intended for educational purposes only. The information presented here is not a substitute for proper medical attention, diagnosis, or treatment by a qualified healthcare professional. Always seek the advice of your healthcare provider before starting or making any changes to an existing treatment plan, exercise program or dietary regimen, and before using nutritional supplements.
~ Dr. Sarah Williams ~ Concord & Nantucket, Massachusetts ~
~ Dr. Sarah Williams ~ Concord & Nantucket, Massachusetts ~