Vitamins are micronutrients that are essential for the healthy functioning of human bodies.
Vitamin D is a unique vitamin that is available through an environmental source – sunlight, When the UV rays (UVB) from the sunlight fall on our skin, Vitamin D is produced in the skin and is then absorbed in the blood.
Vitamin D is one of many vitamins our bodies need to stay healthy. This vitamin has many functions, including:
To ensure adequate vitamin D levels in pregnant women, The Endocrine Society recommends a daily supplementation with at least 1,000-2,000 IU vitamin D, along with prenatal vitamin containing 400 IU vitamin D.
To satisfy the requirements of an infant who is fed only breast milk, The Endocrine Society recommends 1,500-2,000 IU/day for the mother, they may need 4,000–6,000 IU/day if they choose not to give the infant a vitamin D supplement.
To treat vitamin D deficiency in adults, The Endocrine Society recommends a weekly supplementation with 50,000 IU for 8 weeks, to achieve a blood level of 25(OH)D above 30 ng/ml (75 nmol/L), followed by maintenance therapy of 1,500–2,000 IU/day.
To ensure adequate vitamin D levels in adults at high risk of Vitamin D Deficiency, The Endocrine Society recommends a daily supplementation with 1,500–2,000 IU/day, thus preventing vitamin D deficiency.
As the name goes, a lower level of Vitamin D in the body is termed as Vitamin D deficiency. Then what is Vitamin D insufficiency? Well, it’s the blood level of Vitamin D measured in the form of serum 25-hydroxy-Vitamin D (calcidiol) that determines it.
Vitamin D comes from two main resources: direct sunshine and select foods.
When the sun is strong, many people are advised to stay out of direct sunlight without sunblock. Sunblock keeps your skin safe from harmful UV rays, but it also blocks your body’s ability to produce vitamin D (an SPF of 8 has been reported to reduce production of vitamin D by 95%).
The answer depends on several factors, including your age and where you live.
To get enough vitamin D from the sun or food alone is difficult. For example, you will need to eat at least a carton of eggs just to get your minimum daily intake. That’s a lot of eggs! This is why supplements are a welcomed option.
Life Stage Group | Daily Requirement | Daily Upper Limit |
---|---|---|
9 – 18 years | 600 – 1,000 IU | 4,000 IU |
Adults | 1,500– 2,000 IU | 10,000 IU |
Pregnancy / Lactation | 1,500– 2,000 IU | 10,000 IU |
Mother’s requirement, 4,000–6,000 IU/d (mother’s intake for infant’s requirement if infant is not receiving 400 IU/d).
*Endocrine Society Guideline
References:
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4. Complement Ther Clin Pract. 2012 May; 18(2):85-8.
5. J Clin Endocrinol Metab. 2011 Dec;96(12):3908.
6. Curr Osteoporos Rep (2012) 10:4-15, Vitamin D in the new millennium, Sunil J. Wimalawansa.