There are many reasons for nutrient deficiencies. When it comes to B12, it needs intrinsic factor, which is produced in the stomach for absorption later on in the intestines. As we grow older, we produce less intrinsic factor. If you’re following a vegan diet, your B12 will be low because we only get it from animal protein.
Bariatric surgery is notorious for causing deficiencies in vitamins and minerals. Another insult is the chronic use of proton pump inhibitors like Prilosec and Nexium. We need stomach acid to digest food and absorb nutrients. Long term users of PPIs should not be surprised if they’re low in critical micronutrients.
When it comes to vitamin D, we don’t get much from diet. You’d have to eat pounds of salmon, sun-ripened shiitake mushrooms, and drink lots of fortified milk to get as much vitamin D as you need. Best to get some from appropriate sun exposure between the hours of 11:00 AM and 1:00 PM daily. Don’t get sun burned. Several minutes a day should do it. Or take a vitamin D supplement, especially in winter months.
Another reason for chronic low levels is malabsorption. Certain medical conditions that cause fat malabsorption such as celiac disease, Crohn’s disease, cystic fibrosis, even gastric bypass surgery, make fat-soluble vitamins such as vitamin D less bioavailable.
Do you have liver or kidney disease? Calcitriol, the active form of vitamin D, is dependent on optimal liver and kidney function for its conversion.
If you are African American, you should know there may be genetic differences in the binding of vitamin D to receptors, causing lower levels.
Are you overweight or obese? Vitamin D is sequestered by fat cells, decreasing bioavailability.
Finally, are you taking a statin? Cholesterol is the substrate necessary for vitamin D synthesis. Taking Lipitor or other statins may inhibit your vitamin D levels from increasing.
Moreover, certain medications activate the destruction of vitamin D to its inactive form, calcitroic acid. These drugs include anticonvulsants, glucocorticoids, antirejection medications (following organ transplant surgery) and antiretroviral medications used in HIV/AIDS.
A qualified nutritionist can help you navigate your concerns and provide the necessary supplements and recommend diet changes based on your individual needs.
To your health!
Leyla Muedin, MS, RD, CDN
