When my husband and I moved to Washington, we looked forward to wilderness, skiing, hiking and a great outdoor lifestyle.
We did not realize that this new lifestyle – including shorter days in winter, and our usual healthy habit of sun protection in the summer – would include Vitamin D deficiency.
As Vitamin D deficiency began to appear in the medical news more frequently, I started taking a supplement. A month later, even after a vacation in the sun, my own levels were just barely normal.
Your skin makes Vitamin D – the “sunshine vitamin” – when exposed to ultraviolet rays in sunlight, and then your kidneys change it to a usable form that your body can store.
It helps you absorb and use calcium and phosphorus, reduces inflammation and may also affect the function of the immune system. In children, healthy Vitamin D levels have been shown to reduce the risk of juvenile diabetes.
I have listened with interest as some patients with chronic pain and low Vitamin D levels report less pain, better sleep and fewer depression symptoms after supplementation. There is no clear evidence as to how or why people have these results.
Perhaps a Vitamin D boost is part of why many people feel better after a sunny vacation in the winter? It may not happen for everyone, but I do not argue when I hear these kinds of stories from patients.
Back in the day, children were given cod liver oil (which contains Vitamin D) to prevent rickets caused by Vitamin D deficiency. Vitamin D is added to many dairy products for the same reason.
The adequate intake value of Vitamin D for people under age 50 is 200 IU per day. But studies have shown that may be too low, and a large group of Vitamin D researchers has asked the government to re-examine, and raise, this value.
Higher supplemental doses of Vitamin D are likely needed in children to prevent disease. The American Academy of Pediatricians recommends that exclusively breast-fed infants receive a supplement of 400 IU per day of Vitamin D from birth until they are weaned to Vitamin D fortified formula, or until they are a year old and drinking enough milk.
Despite the almost daily reports of new problems associated with low Vitamin D, the recommended dose is not likely to be changed until more research is done.
While waiting for the recommendations to change, what should you do?
First, eat more foods rich in Vitamin D, including cold-water fish (particularly fatty fish such as wild salmon, halibut and cod), eggs and fortified foods like milk, which has 100 IU of Vitamin D per cup.
When I lived in Kodiak, Alaska, I saw fewer patients with low Vitamin D levels because fish is a large portion of the typical diet there. Fish oil capsules have some Vitamin D and are an alternative to eating more fish, but I do not recommend large amounts of cod liver oil supplements because they are often too high in Vitamin A.
When a change in diet is not enough, I recommend that my adult patients increase their daily intake of Vitamin D3 to at least 1,000 IU. Most multivitamins have 400 IU of Vitamin D2 or D3; note that your body uses Vitamin D3 more readily.
People who work or play outdoors may need less in the summer. But decreases in sunscreen use or increases in sun exposure are not a good idea because the risk of skin cancer is still very real.
Talk to your doctor about specific needs for you and your children and discuss whether you should consider supplements. Taking too much Vitamin D, like anything else, can be hazardous. Vitamin D is stored in fat and can build up in your body if you take too much.
How much of the benefits being seen in some studies (and in my office) are from increased Vitamin D levels, and how much are due to the lifestyle that leads to those levels – eating healthy, exercising outdoors and maintaining a healthy body weight – is not yet known.
I remind my patients (and myself) that supplements can never take the place of a healthy lifestyle.