By Dr. Zelalem Debebe Dietitian, E-Green Life, Addis Ababa
Going down the list of vitamins we know, of the English alphabets, and 4th down the list is Vitamin D. Unlike other vitamins, food is not a good source of this vitamin unless it is specifically fortified (added vitamin to food to increase the nutritional value). Most of us know sunshine is the main source. A specific wavelength of the sun’s UVB (ultraviolet B) ray initiates the synthesis of vitamin D from the basic cholesterol element found in our skin. This then undergoes several pathways and is converted into active vitamin D for use in tissues.
For a long time now, mothers have been advised to expose their infants’ skin to ‘early morning’ sunlight for a few minutes by their healthcare providers. As the consequences of vitamin D deficiency is usually known as rickets ‘a uniquely children’s problem’, the advice has not covered adults.
When children grow, they are expected to get adequate Vitamin D from the exposure they get from playing ‘outside’ which is true only if they do this regularly throughout their life. However, when children grow and become ‘teenagers’ and ‘adults’, they actually shy away from the sunshine. This may be due to time constraints, the exceptionally hot sunshine once the time passes 9AM (nowadays especially) or the mistaken belief that Vitamin D is not as important in adults.
Well, Vitamin D is even more important especially as more and more studies indicate that it has a function in maintaining our immune system. Low levels of vitamin D, which is not low enough to be called ‘deficiency’, has been associated with increased risk of Autoimmune diseases (e.g. rheumatoid arthritis), Diabetes (especially Type 1 Diabetes), higher risk of infections (especially respiratory tract infections, higher susceptibility to TB etc.) and cancers.
By Dr. Zelalem Debebe, Dietitian, E-Green Life, Addis Ababa
While the advice to improve the Vitamin D levels in children is working, those at greater risk now are mostly women, and people who cover up regularly for religious or other reasons and the elderly.
Even though we live in a country with ’13 Months of Sunshine’ we need to harness this to our benefit. In dark skinned people, exposure to sunshine does not help us make as much vitamin D as in white skinned people. We may need to sit in the sun with some skin exposure (face, neck and arms may suffice) for at least 15 - 20 minutes daily to be able to make adequate amounts of vitamin D. The best time of the day is when our’ shadow’, is shorter than our actual height! This may coincide with 10am -11am. Too early in the morning, or too late in the evening when the sun is sweet but not strong means, the necessary wavelength of UVB will not reach ours skin for the synthesis of Vitamin D.
Egg, dairy (milk, cheese), oily fish (sardines) can be moderate sources of Vitamin D but may contribute to about 10% of what we actually need regularly. So a good walk in the sunshine will give us Vitamin D as well as a good dose of exercise (free!) which has a whole host of benefits.
Enjoy the sunshine -Happy walking!!