When I was studying nutrition over a decade ago, we learnt that the functioning of D was to support the absorption and action of Calcium in it's various roles. The past decade has seen an impressive amount of research into this compound mainly because it seems to have impacts on the body beyond that of just an ordinary vitamin. Vitamin D is now being referred to as a hormone since it is manufactured in the body from sunlight.
This is due to the fact that Vitamin D Receptors (molecules necessary for it's entry into cells) are located in over 30 different tissues in our body! This means that we have probably just hit the tip of the iceberg in determining what roles it really plays in our bodies.
Evidence shows that maintaining adequate levels of vitamin D during pregnancy, nursing, infancy and childhood lowers risk of the child developing Type 1 Diabetes and other auto-immune disorders. Vitamin D is required for bone and teeth mineralization, optimal functioning of blood, acid base balance, essential for thyroid hormone action, maintenance of muscle strength, brain development in children, health of our immune system, optimal functioning of cardiovascular and respiratory systems, insulin production / regulation and involvement in cell multiplication at a genetic level. This is what science is exploring so far......there are still miles to go.
What's worrying is that in sunshine-rich India, over 40 % of Indians are estimated to be D-ficient....
Some of the risk factors:
- Not getting at least 15 minutes of direct sun exposure daily, remaining indoors for most of the sunlit hours
- Covering up and applying sunscreen at all times when in the sun
- Having a darker complexion (more melanin, more time it takes for skin to produce Vit D)
- Being older than 50 years of age (Capacity to produce Vit D from sunshine is reduced as one ages)
- Being obese or even just overweight (more fat tissue under skin reduces Vit D production)
- High pollution levels in your city (smog reduces penetration of UV B rays)
- Being on a severe low fat diet
Some of the disease risks raised by D-ficiency....
- Rickets – a bone mineralization disorder seen in children, once rare, again on the rise. The condition is called osteomalacia if present in adults
- Hypertension, sudden death from heart attack and stroke
- Multiple Sclerosis, Type 1 Diabetes, Rheumatoid Arthritis, Inflammatory Bowel Disease and other auto-immune disorders in children and adults
- Asthma and respiratory infections especially in children
- Several types of Cancers.
- Decreased thyroid function leading to goitre
The risk factors are so much the norm in our daily lives and so are the consequences. Just evaluate your own risk to see where you stand. You could be dealing with some of the possible consequences already or just having niggling back / joint pain. A lot of otherwise healthy adults and children have also been found to have low D levels in blood – setting them up for an unhealthy future.
So how can you guarantee adequate Vitamin D levels in your body? Get your serum D3 levels checked. If deficient, supplementation is key – under your doctor's guidance of course. Especially if already suffering from it's impacts on your health.
Unfortunately, foods are not a great source of this vitamin. Some foods that are relatively higher in D content......
- Fatty fish – Raawas (salmon), Bangda (mackerel), Chura (tuna), Bhing (herring), Mathimeen (sardines)
- Dairy – milk and cheese
- Egg yolks
- Mushrooms (few varieties like Shiitake)
- Cod Liver Oil
For vegetarians, the options are pretty slim – cheese, mushrooms and cod liver oil supplements. For even meat eaters, food intake can contribute only a maximum of ten percent of our requirement – so the main source is still sunshine.
The Root Causes.......We Indians are complexion-conscious and don't wish to be tanned so we use sunscreen – an additional concern may be skin cancer which of course is relevant but we needn't shy away from sunshine for fear of it. Also, more worryingly, many doctors in India are recommending supplementation without really dealing with the basic issue of sun exposure. The concept of food fortification with D hasn't taken off in India the way it is in the West.
The Reality.........Our country mostly lies below the 35 degree latitude line, towards the equator. We get enough UV B radiation from the sun almost the whole year. This is a sunshine vitamin and our bodies are capable of producing it! The focus should be on how to empower our skin to make more than enough for our needs, not solely rely on artificial supplementation.
The Final Prescription:
Go out in the sun every other day without sunscreen for at least 15 minutes (or less if your skin burns easily). If you have a dark complexion, 20 minutes. Make this a conscious, regular practice – otherwise it will go the way of other healthy habits you started...and stopped. A sign that your skin is absorbing the UV B rays is a slight pinkish hue (erythema) developing. Stay in the sun for at least 5 to 10 minutes after your skin turns pinkish. Make sure you expose your arms, hands, neck, face and feet if not more. This ensures production of the amount you'll need for a couple of days as well as creating a store for future use. Finally 3 or 4 times a week, every week is what you should be aiming at.
Ensure your whole family does the same – encourage your kids to take up out door games and activities. Many schools in urban centres don't have any playground area.... this means kids have to be indoors all day – if this sounds like your child's school – ensure their sun exposure yourself. If your child's school has time dedicated to outdoor play, no need to worry – but check that it is not excessive and does not occur at the hottest time of the day or else your child could wind up with dehydration or sun stroke.
If you live in India, stock up on sunshine in spring, summer and autumn months. In winter, except for cloudy, foggy and smoggy days, you should be able to catch some rays during peak daylight hours. Take supplements only with your doctors consent and only in the dosage recommended.
Interesting Facts :
- Of the different types of radiation from the sun – the specific wavelength of Ultra Violet 'B' rays are required for Vit D production
- 7-dehydrocholesterol and ergosterol are the 2 precursors of D found in skin. On receiving UV B radiation, they form Vitamin D3 which then travels first to the liver and then the kidney to finally become the active form that the body uses.
- Using sunscreen reduces absorption of UV B by as much as 95% on that patch of skin
- Best time for sun exposure is between 10am to 3 pm, even on cloudy days
- Exposing arms, hands, feet, neck and face to the sun means around 25% of your skin's surface is soaking the rays.
- UV B rays don't pass through glass or clothes!
- While Vitamin D toxicity is possible through irresponsible supplementation, the body has a natural control mechanism for Vitamin D produced by skin so that this can never cause toxicity
- Vitamin D is used in the treatment of Tuberculosis. It also has anti-inflammatory effects in the body.