August Issue 2012
Vitamin D or Die?
The main source of vitamin D is exposure to the sun. Yet sun-drenched Pakistan is showing a high incidence of vitamin D deficiency. In a sample of 119 out-patients, some doctors at the Aga Khan University Hospital (AKUH) found that 92% suffered from vitamin D deficiency. Nearly 62 percent had severe deficiency and 50% were asymptomatic — i.e they exhibited no symptoms to indicate deficiency (Journal of Pakistan Medical Association-JPMA).
Newsline talked to Dr Jaweed Akthar, professor and section chief of endocrinology at Aga Khan University Hospital ( AKUH), who assured us that vitamin D deficiency is a worldwide problem that is not confined to Pakistan. Having said that, a number of tests have been done on small samples of staff and patients at AKUH and it has been found that about 80-90 percent do suffer either insufficiency or deficiency of vitamin D, and this also true of otherwise healthy individuals.
Normal vitamin D levels are about 30ng/ml. Between 20-30 ng is considered insufficient vitamin D and less than 20 is considered a deficiency. Vitamin D is absorbed through sunlight and diet. The reason a lot of Pakistanis suffer from a D deficiency is partly — and ironically — because of a lack of exposure to the sun. That interestingly, owes in part to our cultural milieu. We, in Pakistan, are covered most of the time, especially women, and thereby sun rays do not directly hit our skin and even if we have the choice, we do not go out in the sun for any prolonged period, let alone lie in the sun. Also, pollution levels cut the effectivity of UV rays. Furthermore, we are dark-skinned and melanin reduces the vitamin D conversion in the skin.
To add to all of these is our diet. It is not fortified with vitamin D as in the West, where milk and cereal are fortified foods. Also, liver and fatty fish like sardines rarely feature in our diet. Even breast milk needs to be supplemented with vitamin D. Thus you need to consume large quantities of the D sources e.g fish, to get the recommended levels of the vitamin.
Vitamin D deficiency can be asymptomatic but not always so. And symptoms vary and include from non-specific aches and pains, to pain in the bone and aching joints and if it is a very severe vitamin D deficiency, it can cause fractures. Vitamin D supplements have been shown to be useful for bone strength, bone density and muscle strength. Improving muscle tone can prevent people from falling, and hence prevent fractures. Currently there is a lot of research underway on vitamin D and its links to other conditions like heart disease, diabetes and cancers. However, so far no concrete evidence has emerged to indicate that adding vitamin D to medical treatments for these conditions will prove more efficacious.
One of the roles of vitamin D is to facilitate calcium absorption from the gut. Vitamin D and calcium are important for the bones and vitamin D deficiency can lead to a weakening of the bone, resulting in a disease called osteoporosis. If the bone becomes deficient in calcium, osteomalacia may occur. Osteomalacia in children is known as rickets and may cause growth deformities and bony changes. Osteoporosis is quite common in Pakistan, but vitamin D is just one of many factors that may cause it. Rickets and osteomalacia are less common and if caught in time can be cured with vitamin D replacement.
While vitamin D deficiency is so common, the blood test to check for it is expensive. Treatment, meanwhile, is less so and includes capsules or injections. The injections which are administered in high doses are relatively economical. However, it is important not to take too much vitamin D as that can also cause hypercalcemia, among other things.
Vitamin D, referred to as the sunshine vitamin and/or the bone vitamin, may also be linked to mental disorders like depression and schizophrenia, according to the writings of Aga Khan University Hospital’s psychiatrist Dr Mukesh Bhimani in an article in the JPMA. It is not clear, however,if low levels of vitamin D cause depression or if depression causes vitamin D levels to fall —perhaps patients with poor mental health may be more likely to stay indoors and avoid the sun. Or it could be a third factor that causes both, like genetics.
Scientists in Copenhagen say that vitamin D plays an important role in “boosting the immune system.” And according to an article in The Telegraph, vitamin D activates the T-cells so they are able to recognise and fight off infection. Some doctors also link a D deficiency with autoimmune diseases like multiple sclerosis and rheumatoid arthritis.
“For years we have heard that we need to protect ourselves from the sun to avoid melanoma and skin cancer. Cancer Research UK recognises the need to balance skin cancer prevention with the generation of adequate vitamin D, but has specified that the skin efficiently produces vitamin D at levels of sun exposure below those that cause sunburn…when it comes to sun exposure, little and often is best,“ says an article in Lancet, a leading medical journal.
This article was originally published in the August issue of Newsline.