Diet & Nutrition Vitamin D

• What is Vitamin D?
• Function
• Signs of deficiency
• Non-meat food sources
• Notes
• Caution

What is Vitamin D?
Vitamin D (otherwise known as calciferol) is a fat-soluble vitamin which is obtained either through the diet or simply by exposure to sun light. The human body can produce Vitamin D; sunlight creates a reaction producing vitamin D3 (cholecalciferol) which is then converted by the liver and kidneys into biologically active metabolites. This process is so efficient that according to the UK Government's Committee on Medical Aspects of Food Policy Panel on Dietary Reference Values 'No dietary intake (of Vitamin D) is necessary for individuals living a normal lifestyle'(1). However , please refer to Notes below.

Function

• Prevents Rickets ( a childhood disease) - symptoms include malformed bones, bowed legs, late tooth development, listlessness
• Regulates bone formation and repair

Signs of deficiency

Non-meat food sources

Notes
Supplementation is generally not necessary in the Uk except for the following categories of people:

• Elderly people often do not expose sufficient skin to sun light in the UK. The Department of Health therefore recommends a supplement of 10mcg daily.
• Pregnant and lactating women are also advised by the Department of Health to take a 10mcg dietary supplement.
• Infants between six months -3 years because many children do not receive sufficient exposure to sun light. The Department of Health recommend children up to the age of two years receive a supplement containing 7 mcg of vitamin D daily.
• 1 International Unit (IU) of vitamin D = 0.025mcg
• Vitamin D2 & D3 have the same biological activity.

Caution
Vitamin D is extremely toxic in excessive dosages. It is therefore not advised to take any amount over and above the Recommended Intake. Symptoms of overdose include: