There are 3 types of vitamin D namely D1, D2 and D3. Vitamin D3 is the type that can only be produced in skin that is exposed to sunlight. It is one of the only vitamins produced naturally by the body. To have the body produce adequate amounts, an average of 1 hour exposure to sunlight per week is needed. Surprisingly, many people are still not producing the beneficial amounts.
Vitamin D deficiency is proven to lead to 3 main diseases which are
childhood disease characterized by impeded growth, and deformity, of the long bones.
a bone-thinning disorder that occurs exclusively in adults and is characterized by proximal muscle weakness and bone fragility.
a condition characterized by reduced bone mineral density and increased bone fragility.
Vitamin D malnutrition is also linked to several chronic diseases like high blood pressure, tuberculosis, cancer, periodontal disease, multiple sclerosis, chronic pain, depression, schizophrenia, seasonal affective disorder and several autoimmune diseases.
Be aware of the risks involved. Get some sun. The older you get the more you need it.
Here’s the recommended daily vitamin D intake according to the US Dietary Reference Intake.
- 1 to 50 year olds = 5 micrograms/day or 200 IU/day (IU is the International Unit for measuring vitamins)
- 51 to 70 year olds = 10 micrograms/day or 400 IU/day
- Past 70 year olds = 15 micrograms/day or 600 IU/day
Other facts about vitamin D absorption that you should know are :
- Obese individuals may have lower levels of the circulating form of vitamin D, probably because of reduced bioavailability, and are at higher risk of deficiency.
- Patients with chronic liver disease or intestinal malabsorption disorders may also require larger doses of vitamin D (up to 40,000 IU or 1 mg (1000 micrograms) daily).
- The use of sunscreen with a sun protection factor (SPF) of 8 inhibits more than 95% of vitamin D production in the skin
- Dark-skinned individuals tend to block more sunlight to be absorbed even at higher latitudes, thereby increasing the risk of vitamin D deficiency.
- Individuals such as certain female residents of conservative Muslim nations in the Middle East clad in full body coverings during all their outdoor activity are at much higher risk of vitamin D deficiency.
Food that is rich in vitamin D are :
- 3 ounces of mushrooms exposed to 5 minutes of UV light after harvesting provides 2700 IU. This is one of the very few natural sources for vegetarians.
- 1 tablespoon of cod liver oil provides 1,360 IU. Most fish liver oil has the same amount.
- 3 ounces / 85 grams of catfish brings 425 IU.
- 3.5 ounces of cooked salmon supplies 360 IU.
- 3.5 ounces of cooked mackerel gives 345 IU.
- 1.75 ounces of drained sardines canned in oil produces 250 IU.
- 3 ounces of tuna canned in oil presents 200 IU.
- 3.5 ounces of cooked eel yields 200 IU.
- A glass of vitamin D fortified milk contains 100 IU.
- 1 whole egg supplies about 20 IU.
Having enough vitamin D in the body contributes to a lot of benefits including
- regulating calcium and phosphorus levels in the blood by promoting their absorption from food in the intestines, and by promoting re-absorption of calcium in the kidneys.
- promoting bone formation and mineralization and is essential in the development of an intact and strong skeleton.
- inhibiting parathyroid hormone secretion from the parathyroid gland. Excessive secretion leads to kidney diseases.
- affecting the immune system by promoting immunosuppression, phagocytosis, and anti-tumor activity.