If you have kicked the smoking habit, you have very good reason to be proud and optimistic. You may look forward to many benefits, including improved health. A decrease in vitamin D levels in your blood is not associated with quitting smoking. Overwhelming evidence supports the contrary: smoking causes a decrease in vitamin D levels. If you have quit smoking and have found you have a decreased level of vitamin D in your blood, it is likely due to another cause. Consult your doctor to determine the cause and the remedy.
Sources of Vitamin D
Human beings receive vitamin D by absorbing ultraviolet B rays from sunlight, by eating foods that contain the nutrient or by taking vitamin supplements. For most people, diet and sunlight is enough to deliver the vitamin in adequate doses. Foods that contain vitamin D include fatty fish like salmon and tuna, milk, eggs, Swiss cheese and vitamin D-fortified products like orange juice and yogurt. Adults should take in about 400 International Units of vitamin D per day, according to the daily values set by the U.S. Food and Drug Administration.
The Sunshine Vitamin
Vitamin D also is called the sunshine vitamin because the UVB rays in sunlight penetrate the skin and react with a cutaneous compound called 7-dehydrocholesterol. This reaction converts the compound to pre-vitamin D, which later becomes vitamin D. To spur this process, make sure you expose bare skin on your arms, face, legs or back to sunlight for five to 30 minutes per day, between the hours of 10 a.m. and 3 p.m. The vitamin D your body creates is stored in the liver and fatty tissues. If you previously stepped outdoors to smoke you may now miss that time out in the sun. And, the sunlight coming in through your office window doesn't count; the glass blocks UVB rays.
Risk Factors for Vitamin D Deficiency
Since smoking may have caused you to have a vitamin D deficiency, you should see improvement now that you have quit the tobacco habit. However, factors other than smoking may affect your vitamin D level. If you have a darker sink tone you have a greater risk of developing a vitamin D deficiency because the melatonin in your skin blocks the absorption of the UVB rays. Additionally, older adults may produce less vitamin D because their skin cannot synthesize vitamin D as efficiently as younger people. Some medical conditions that are associated with fat malabsorption, like certain liver diseases, Crohn's disease and cystic firbrosis, also put a person at greater risk of vitamin D insufficiency. Weight appears to be a factor, as obese people may require more vitamin D to maintain an adequate level than people of normal weight. People who have had gastric bypass surgery may become deficient, too, because the part of the upper small intestine that absorbs vitamin D is bypassed in their digestive process.
Health Risks of Vitamin D Deficiency
Each individual may experience different symptoms associated with a vitamin D deficiency, including weak bones, chronic pain, depression and infections. Vitamin D deficiency has been linked to osteoporosis, a medical condition that causes bones to become weak and brittle. Whereas inadequate calcium intake may cause osteoporosis, vitamin D aids in calcium absorption. Smoking decreases vitamin D levels in your body, possibly interfering with calcium absorption. Research over the past 20 years strongly indicates a direct link between tobacco use and decreased bone density, which may lead to osteoporosis. You should have lessened your risk since you have quit smoking; however it may take a few years before you are at the lower, former smoker's risk level. Other studies have found that vitamin D may have a protective effect against certain cancers, like cervical cancer, and diabetes. However, be cautious not to consume too much vitamin D, as excesses may cause other health problems like calcification in the arteries and in tissue, leading to heart and kidney disease. Research also suggests a link to pancreatic cancer and other causes of mortality. The risk of vitamin D toxicity is most predominant with the use of dietary supplements, and normal daily doses through foods and sunlight is not a factor. To learn how to properly manage a vitamin D deficiency, talk to your doctor.
References
- Vitamin D Council: Cervical Cancer, Patient Friendly Summary
- Osteoporosis International: High Prevalence of Vitamin D Deficiency Among Healthy Saudi Arabian Men: Relationship to Bone Mineral Density, Parathyroid Hormone, Bone Turnover Markers, and Lifestyle Factors
- Journal of Proteome Research: Proteomic Profiling of Human Plasma by iTRAQ Reveals Down-regulation of ITI-HC3 and VDBP by Cigarette Smoking
- Office of Dietary Supplements, National Institutes of Health: Dietary Supplement Fact Sheet: Vitamin D
- NIH Osteoporosis and Related Bone Diseases National Resource Center: Smoking and Bone Health
