Vit D is also known as sunshine Vitamin as sunshine helps to synthesize this hormone. Vit D is a fat soluble Vitamin it’s unique because it functions as a prohormone and body can synthesize it when sun exposure is adequate. Measures of serum levels (From Vit D3, blood test) reflect endogenous synthesis from exposure to sunlight as well as intake from the diet.
Vitamin D has two main forms: D2 (ergocalciferol) and D3 (cholecalciferol). Vitamin D3 is synthesized in skin by exposure to sunlight (ultraviolet radiation) and obtained in the diet chiefly in fish liver oils and egg yolks. In some developed countries, milk and other foods are fortified with vitamin D. Human breast milk is low in vitamin D, containing an average of only 10% of the amount in fortified cow’s milk. Requirements for vitamin D increase with aging. Vitamin D is a prohormone with several active metabolites that act as hormones. Vitamin D3 is metabolized by the liver to 25(OH)D, which is then converted by the kidneys to 1,25(OH)2D (1,25-dihydroxycholecalciferol, calcitriol, or active vitamin D hormone). 25(OH)D, the major circulating form, has some metabolic activity, but 1,25(OH)2D is the most metabolically active. Inadequate exposure to sunlight may cause vitamin D deficiency. Deficiency impairs bone mineralization, causing rickets in children and osteomalacia in adults and may contribute to osteoporosis.
There was a time when my mother use to tell me that they would not waste sunshine and spent lot of time outdoors. But now we have moved on to indoor video games, play stations, work in air condition offices and workout in gyms!
Vit D deficiency is now seen in all age groups while previously it was limited to post menopausal women, sad but true.
Causes of deficiency
- Less or no exposure to sunlight
- Poor intake of vitamin D rich food
- Excessive use of sunscreen
- Following fad diets with zero oil intake
- Minimal exposure of skin to sunlight such as wearing full sleeves, covering oneself in totality.
- Staying indoors all the time in air conditioned offices; offices executives, software engineers, night duty workers
- Darker skin
- Chronic illness where one is bedridden
Consequences of deficiency
- Poor bone health leading to osteopenia and osteoporosis
- Increased risks of fractures in post menopausal women
- Poor teeth health
- Poor calcium absorption due lack of the precursor ie. Sunlight
- Weight gain
- Poor insulin secretion, hence can be prone to develop diabetes
- Poor immunity
- Increased cancer risk
- Increased risk of Alzheimer’s and Rheumatoid arthritis
- Increased blood pressure.
Now as you all are aware of its causes and consequences so just don’t run to the nearest pharmacy to pick up supplements, it’s much better to,
- Get your Vit D3 levels checked!
- Taking supplements(many doctors recommend 800IU of Vitamin D3 a day)
- Add VIT D to your diet with naturally as well as fortified Foods.
- Oily fish such as salmon, tuna
- Fortified food such as Orange juice, soy milk, egg yolk and Organ meat
- Spend at least 15-20 mins in sunlight without sunscreen before 9 or after 3 pm.
Vitamin D is endogenously produced, circulates bound to its own specific binding protein, and is converted in situ to the active form, 1, 25(OH)2 vitamin D, in target tissues. Receptors for vitamin D are widely distributed, and these target tissues include macrophages, monocytes, bone, intestine, skeletal muscle, brain, and heart. Clinical studies of vitamin D supplementation at doses of 700 to 800 IU/d have shown beneficial effects on reducing hip and nonvertebral fractures and in improving muscle strength and reducing falls. There is also epidemiological evidence for reduction in colon, breast, and prostate cancers with higher vitamin D levels. Therefore, the potential role(s) of vitamin D are much broader than calcium regulation alone.
Vitamin D deficiency appears to be more common than previously thought, especially in the elderly population. This condition is often unrecognized by clinicians; therefore, assessment of vitamin D status with serum measurements of 25(OH) vitamin D levels for a broader range of patients should be encouraged. Supplementation at a dose of 800 IU/d vitamin D appears to have a positive impact on reducing fractures and falls. Vitamin D toxicity is very uncommon, and there is a wide safety margin at these higher supplement doses.
Reena Valecha, OT