Vitamin D- FAT SOLUBLE- STORED IN BODY- DON'T NEED DAILY

Question 1

What are the SOURCES of Vitamin D?

Answer 1

Naturally in ANIMAL foods
-Oily fish -Liver
-Cheese
-Butter
-Milk- quantity depends on time of year
-Breakfast Cereals
-Marg- Fortified by LAW

SUNLIGHT
-non- dietary factor
-Vitamin D formed when a PIGMENT under the skin is converted to Vitamin D by the action of SUNLIGHT

Question 2

What are the FUNCTIONS of Vitamin D?

Answer 2

1). Vitamin D is needed for the GROWTH and MAINTENANCE of bones and teeth- help calcium absorb FROM the INTESTINE to the BLOODSTREAM.
2). Vitamin D plays a key role in the prevention of MUSCLE WEAKNESS.
3). Vitamin D plays a direct role in REGULATING BLOOD PRESSURE by INHIBITING the activity of a system- RENIN-ANGIOTENSIN SYSTEM.
4). Vitamin D plays an important role in the regulation of the IMMUNE SYSTEM.
5). Vitamin D is required for the UPTAKE OF CALCIUM and PHOSPHORUS by teeth and bones.

Question 3

What are two types of vitamin D?

Answer 3

•Cholecalciferol- VIT D3
-Natural form of the vitamin- occurs in foods (formed by action of sunlight)

•Ergocalciferol- VIT D2
-Synthetic form of the vitamin- some activity as the natural form
-produced by action of light on yeast

Question 4

What is a deficiency in Vitamin D?

Answer 4

•SKELETAL DEFORMITY
-unnatural limb posture, delayed ability to stand up, knock knees/ bow legs

•RICKETS- children

•OSTEOMALACIA- adults

•OSTEOPOROSIS- not a deficiency
-After 30, CALCIUM GRADUALLY GETS LOST from bones- become weak, more PORUS and brittle
-Women go through rapid bone loss after menopause (oestrogen levels decreases)
-Peak bone mass- around 30

-Osteoporotic bones will easily fracture

ASIAN PEOPLE
-Asian diet- low in Vitamin D- culture doesn’t expose to sun

Question 5

What does an excess of Vitamin D lead to?

Answer 5

SYMPTOMS OF TOXICITY:
•Loss of appetite
•Nausea
•Vomitting
• Hypertension
• Too much vitamin D- cause excessive calcium to be deposited in soft tissues, eg kidneys

HYPERVITAMINOSOS D- results in kidney damage

Question 6

Factors affecting absorption- BIOAVAILABILITY

Answer 6

•Cheap diet- poor selection of foods/ low quality foods
•Lack of sunshine

Question 7

What are the effects of cooking?

Answer 7

•Vitamin D is STABLE and INSOLUBLE in water- only mildly affected by cooking

•ALCOHOL- causes more Vitamin D to be excreted

Question 8

Advice to older people to reduce Vitamin D deficiency?

Answer 8

•Supplementation- 10mg a day- esp if housebound

•Sunshine- encourage time outside in sun- synthesis of Vitamin D- due to action of sunlight on skin

•Diet foods rich in Vitamin D- eg eggs, milk, oily fish-
easy to eat and digest

•Fortified foods- margarine- fortified with vitamin D

•Don’t consume too much alcohol- causes Vitamin D to be excreted in urine rather that being stored in body

Question 9

Those who may be deficient?

Answer 9

•Elderly- housebound- can’t receive natural form

•Asian Culture- diet is low

•Pregnant women- must be prescribed by GP

•Children- prevent rickets