Why vitamin D is so important for people with RA: Part 1
ave you seen the recent news about how Vitamin D may be underestimated for its health benefits and how Americans may be terribily deficient in the vitamin?
We can let the scientists battle that out, but Vitmain D may be important for those of us with Rheumatoid Arthritis.
What is vitamin D?
Vitamin D is a compound that acts like a hormone in the body. It sends chemical messages signaling the intestines to absorb calcium and it regulates calcium uptake by bone cells. Unlike some vitamins, like vitamin C, that begin working in the body immediately after being consumed, vitamin D must be processed by the liver and kidneys into a form (calcitriol) that can attach to vitamin D receptors in most of the body's cells. Your body stores one form of previtamin D, called dehydrocholesterol, in the skin. When your skin absorbs sunlight, it is transformed into previtamin D3 (cholecalciferol). This is the most readily absorbed form of vitamin D. Previtamin D2 (ergocalciferol) is ingested through plant sources.
Why is vitamin D important to me?
Its basic purpose is increasing calcium absorption, which is vital for maintaining healthy bones and preventing osteoporosis (a bone thinning disease) and osteomalacia (a bone softening disease). However, there have been a many research studies over the last decade showing that it also plays an important role in preventing certain cancers like breast, colon and ovarian cancers, heart disease, diabetes and osteoarthritis. It may play a role in regulating the immune system. Low vitamin D levels have been linked to diabetes, high blood pressure and obesity, which all contribute to cardiovascular disease.
Most recently, in the June issue of the Archives of Internal medicine, two different studies linked low vitamin D levels with heart disease and heart attacks. This is also something for people with RA to think about, since the systemic inflammation in people with RA have been shown to increase the risk of death from heart attacks and strokes. In one study of 3,258 patients, those who had the most severe vitamin D deficiencies were two times as likely to die over the 8 year study period (307 patients with severe deficiency verses 103 with high levels of vitamin D). Of those with low vitamin D in general, cardiovascular deaths were the most common (463 patients out of 737 that died). However, the study was inconclusive as to whether the vitamin D deficiency was a direct contributor to the heart-related deaths, or whether increase vitamin D intake would have made a difference, since the average age of the male and female participants was 62 and most of them already had heart disease.
It has been estimated that as much as 50% of the world population is vitamin D deficient. Very recently, a team of scientists in Ireland found that nearly ¾ of the new patients seen at their rheumatology clinic over a six month period had a vitamin D deficiency. Of the 231 patients who agreed to have their vitamin D level checked, 162 (70%) had low vitamin D. Twenty-six percent had a severe deficiency. The difference between the levels of younger and older patients was insignificant and was seen across people with various conditions, including RA, osteoarthritis, osteoporosis and people with backaches. The researchers concluded that a mild-to moderate lack of vitamin D may contribute to some rheumatic conditions, while a chronic severe lack of vitamin D greatly increases the risk of osteoporosis and rickets.
It has been shown that people with RA are at a higher risk for developing osteoporosis, partly because older women are the most common candidates because body changes related to menopause contribute to osteoporosis. Also, certain steroids, like Prednisone, used to treat RA can cause bone loss and RA. Some osteoporosis medications to promote bone growth aren't as effective is a person is vitamin D deficient. These drugs can actually leech vitamin D from the muscles. So it is important for people who are using steroids or osteoporosis medications to talk to their doctors about making sure they get enough vitamin D. Your vitamin D level can be tested with simple blood work.
Read the next installment: How much vitamin D should I consume and how should I get it?