Vitamin D is a fat soluble vitamin important to healthy bones and other bodily processes. Produced naturally in the human body upon exposure to sunlight, it also helps the body more effectively absorb minerals like calcium, iron, magnesium, phosphate, zinc.
There are several forms of vitamin D. As supplements, D2 and D3 are the most common. D2 (ergocalciferol) is synthesized from plants. D3 (cholecalciferol) a the natural form of vitamin D that the human body synthesizes from sunlight. Studies suggest that both are equally effective when taken as vitamin supplements.
Recommended minimum vitamin D intake by age:
--- 1-3 years - 600 IU per day.
--- 4-8 years - 600 IU per day.
--- 9-13 years - 600 IU per day.
--- 14-18 years - 600 IU per day.
--- Adult 19+ (male and female) - 600 IU per day.
--- Adult 71+ (male and female) - 800 IU per day.
--- Adult (female pregnant) - 600 IU per day.
--- Adult (female breastfeeding) - 600 IU per day.
For those who do not obtain adequate amounts from either their diet or exposure to sunlight, vitamin D supplements are an option. Many people think 1000-4000 IU of vitamin D should be the recommended daily supplement intake amount for adults.
Dietary sources with vitamin D content include:
--- Soybean products.
--- Dairy products.
--- Foods with vitamin D added (fortified).
--- Fatty fish (mackerel, salmon, sardines, tuna).
Excessive amounts of vitamin D can result in a malady known as vitamin D toxicity, a fairly rare condition usually associated with intake over 20,000 IU of vitamin D taken daily, over the course of months or years at a time.