Vitamin D is one of the most important nutrients for good health, but getting enough isn't as easy as you might think.
Yarden Tahan, MD, a primary care physician at HonorHealth Medical Group Seventh Street, says vitamin D is needed to absorb and regulate calcium in the body. In addition to being vital to bone health, it aids in muscle function. Vitamin D deficiency may leave you feeling fatigued or cause muscle weakness since muscle contractions require adequate calcium in your system.
Aside from fatty fish like salmon, mackerel and canned tuna, vitamin D isn't naturally present in most foods. Therefore, it's added during processing. Foods most commonly fortified with vitamin D include:
- Orange juice.
The skin creates pre-vitamin D, but sun exposure is needed to convert it to useful vitamin D. "The trick is not getting so much sun that you burn," Dr. Tahan said.
Is there a one-size-fits-all recommendation on how much sun exposure is needed to convert and activate vitamin D? "Not really," she said. "An estimate is about 15 minutes a day. If you have darker skin, you may need to extend that time. If you start to burn, you've been in the sun too long."
Disorders can lead to deficiency
Vitamin D is processed by the liver and kidneys before calcium absorption in the intestines can occur. If you have chronic liver or kidney issues, you may have a vitamin D deficiency that requires supplementation. Some disorders that affect fat absorption such as celiac disease, cystic fibrosis, pancreatic insufficiency and Crohn's disease also can lead to a deficiency.
Vitamin D deficiency can result in decreased bone density, which is more common among older adults. In children, prolonged deficiency can prevent mineralization of bones and cartilage, leading to rickets. This painful weakening of the bones can make them brittle. Bowing of the legs can occur as they struggle to support the body.
"You should get at least 600 international units of vitamin D each day – mainly from food sources," said Dr. Tahan. If you're 70 or older, increase it to 800 international units. If you have liver, kidney or fat absorption issues, ask your doctor about the right dose for you.