FUN WORLD

Vitamin D is a hormone as well as a vitamin. It is quite rightfully called the 'sunshine vitamin' as the sun contributes significantly to the vitamin D content. Vitamin D is a basic with regards to bone health, regulation of muscle health (including skeletal and heart muscle), regulation of immune response, blood sugar levels as well as the regulating metabolism of calcium and phosphorus. On an average, we need about 600 IU (international units) of vitamin D a day, after the age of one.

Production of Vitamin D in Skin and Body
The ultraviolet rays from sunlight touching the skin trigger vitamin D synthesis. Our skin has two primary layers:

1. the outer layer - epidermis
2. the inner layer - dermis

In the epidermis of the thick skin of the soles and palms, there are 5 strata; from the outer to the inner they are: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. It is in the two innermost strata, stratum basale and stratum spinosum, that vitamin D is produced. Vitamin D is activated by the liver and kidneys.

Who has Vitamin D Absorption Problems and Why
The people who are more vulnerable to vitamin D problems are the elderly, obese individuals, and breastfed babies.

• Colored people: People with colored skin need 20 to 30 times more exposure to sunlight than caucasians. People living closer to the equator require less amount of time to create vitamin D than people living further away, where they require longer time of exposure to create the same amount.
• Obese people: Obesity is another factor hindering proper production and utilization of vitamin D, making obese people need twice as much vitamin D than healthy individuals.
• People who work indoors constantly: People who fall ill are the ones who live and work indoors constantly. If there is lack of vitamin D in the body, our immune system becomes defenseless against seasonal flu.

The causes of vitamin D absorption problems are -

• Hindered vitamin D metabolism from anticonvulsant drug therapy
• Celaic disease
• Crohn's disease
• Cushing's disease
• Decreased intake of vitamin D
• Hypothyroidism
• Intestinal surgery
• Lowered levels of essential fatty acids (especially in the intestinal walls)
• Kidney or liver disease
• Multiple renal tubular defects
• Poor exposure to sun
• Ulcerative colitis
• Magnesium deficiency

Factors Affecting UV Radiation Exposure and Vitamin D Synthesis

• Melanin content in skin
• Cloud cover
• Smog
• Time of the day
• Sunscreen
• Season
• Geographic latitude

Other Nutrients and their Connection to Vitamin D
Vitamin D, like all other nutrients, needs several other nutrients and minerals such as magnesium to get converted to an active form in the blood for your body to use it. Vitamin D, a fat-soluble vitamin, is available in a very few foods. However, there are some rich dietary sources of vitamin D like seafood such as catfish, salmon, mackerel, sardines, tuna, eel, whole egg, cooked beef liver and cod liver oil.

Essential Fatty Acids: Adequate amount of essential fatty acids, especially omega 3, are necessary for absorbing vitamin D. The vitamin D from food is absorbed through the intestinal walls.

Magnesium: Some of the symptoms associated with magnesium deficiency linked to vitamin D are -

• Headache
• Insomnia
• Muscle cramps
• Anxiety
• Heart Palpitations
• Constipation

Very high doses of vitamin D can worsen magnesium deficiency. A lot of people may take large doses of vitamin D without bearing in mind the body's need of magnesium.

Other Causes of Vitamin D Absorption Problems
It is best to expose to the sun as much skin on the body as possible, apart from just your arms and legs. Twenty minutes of exposing bare skin to sunlight, twice a week is enough for maintaining the right levels of vitamin D in the body.

• Wearing suncream is another reason why you may be having problems with absorption of vitamin D.
• An ordinary window glass cuts down 95% of ultraviolet-B (UVB) rays. So, if you have sunshine peeping through the window and you're hoping it will help, it won't quite.
• Rickets, a bone-wasting disease, causes vitamin D deficiency, which can aggravate type 2 diabetes by hindering insulin production in the pancreas.

Don't Wash It Away Too Soon
After your skin is exposed to UVB rays, it is best to take a shower some hours later. The reason for this being that after your skin has been exposed to UV, it produces a powdery substance that is absorbed in the skin and is then converted to vitamin D in the body. Having a bath or a shower washes this off, leaving not much scope for your body benefiting from vitamin D, as its production is hampered.

Vitamin D Supplements
When it comes to vitamin D supplementation, the UVB exposure is the best way to synthesize vitamin D, and without forgetting that vitamin D supplements also work best when the capsules are oil based as vitamin D is a fat-soluble vitamin. The oil base makes it easier for your body to absorb vitamin D.