Vitamin D is responsible for maintaining normal calcium levels in the body and mineralisation of bones. The past decade has seen a renewed interest in this vitamin called the “Sunshine Vitamin”. The renewed interest is attributed to the medical fraternity’s increasing realisation that the benefits of Vitamin D extend far beyond healthy bones. Some of its numerous effects have been observed under various clinical conditions and there have been epidemiological suggestions stating that children and adults with adequate or sufficient levels of Vitamin D are atlower risk for hypertension, high blood sugar and metabolic syndrome. Vitamin D level in a person is assessed in terms of 25-hydroxy-vitamin D concentration (It is abbreviated as 25(OH)D and the test too is referred to as such.). This winter, go get some sunshine and give yourself a healthy boost.
What Is The Daily Requirement Of Vitamin D?
The current recommended dietary intake of Vitamin D to maximise bone health and muscle function for patients at risk for Vitamin D deficiency is as follows:
- Infants and children aged 0-1 year: at least 400 IU/day
- Children aged 1-18: 600 IU/day
- Adults aged 19-50: 600 IU/day
- Adults aged 50-70 and above: 600 and 800 IU/day
- Pregnant and lactating women: 600IU/day
(IU is read as the standard International Unit. Contact your physician to discuss your specific requirements.)
What Are The Sources Of Vitamin D?
Vitamin D is produced in the skin naturally in response to ultraviolet B radiation from sunlight. In food it can be obtained from animal sources such as deep-sea fatty fish, egg yolks or liver or from dietary supplements.
Prevalence Of Vitamin D Deficiency
About 50 to 90 per cent of the Indian population reportedly show Vitamin D deficiency of varying degrees. Australia, Middle East, Africa and South America are the other regions or populations known to be affected by Vitamin D deficiency. Of late, countries like the US, UK and Canada too have been contending with significant levels of Vitamin D deficiency in their elderly.
What has come to be the cause for alarm is the increasing prevalence of Vitamin D deficiency in adolescents – an age group that is supposedly healthy and must be healthy as the immediate future’s working population of any society.
- In the US, for example, more than 50 per cent of Hispanic and African- American adolescents (in Boston area) and 48 per cent of white pre-adolescent girls in (Maine area) were found with 25 hydroxy-vitamin D concentration – 25(OH)D that is much below the cut-off level.
- In a study of Vitamin D levels in 3,000 teenagers (both boys and girls), the John Hopkins Bloomberg School of Public Health, Baltimore, found that those with low Vitamin D levels were 2.36 times more likely to suffer from hypertension, 2.5 times more likely to have high blood sugar levels and four times more likely to have Metabolic Syndrome.
- Another trial involving girls aged between 12 and 14 years showed that those with lower Vitamin D levels had lesser muscle strength and weaker physical performance.
Who Are At Risk For Vitamin D Deficiency?
Various factors contribute to Vitamin D deficiency and the risk groups too are varied.
- Exclusively breast-fed infants and children.
- Those aged over 65 years.
- Pregnant women.
- Fully-clothed individuals (like a burqua where hardly any part of the body is exposed to sunlight).
- Home-bound people.
- Institutionalised people.
- Obese individuals.
- Users of sunscreens with high SPF (which block out UVA and UVB rays completely).
- People living at high altitudes.
- People with inflammatory bowel disease, cystic fibrosis, and liver and kidney diseases.
- Those on anti-seizure medications, glucocorticoids, or AIDS medications.
- Dark skinned people, where skin pigmentation decreases the production of Vitamin D.
Tests For Vitamin D Status
Laboratory tests to assess 25(OH)D are available. The result classifies the person’s status as Vitamin D sufficient or insufficient or deficient.
Are Dietary Solutions Available Against Vitamin D Deficiency?
Few foods have substantial Vitamin D content. Outdoor sun exposure and intake of vitamin D supplements leads to higher serum Vitamin D levels than dietary intake of Vitamin D. If sunlight exposure is adequate, the body can produce Vitamin D without the need for supplementation through diet.
Foods That Are Supplemented With Vitamin D
In the US, Canada and parts of Europe, milk, cheese and fruit juices are supplemented with Vitamin D. In India, foods with Vitamin D supplementation are practically nonexistent. It may be cost-effective to introduce food supplementation in India.
The Best Source Of Vitamin D
Without doubt, sensible exposure to sunlight is the best source of Vitamin D.
Vitamin D Deficiency In Adults And Children
Vitamin D deficiency typically presents with bone deformity (rickets) or low calcium levels in infancy and childhood.
In adults, it causes reduced bone mineral density, musculoskeletal pain and weakness. The elderly in particular have increased sway and frequent falls, and are at increased risk for fractures.
Of late, other health issues like cardiovascular diseases, type-2 diabetes, various forms of cancer, and auto-immune conditions too, have been linked to Vitamin D deficiency.