Hiya
Also worthh taking into account is too much vitamin D is as harmful as too little. The body stores vitamin D really well therefore sun exposure does not need to be measured daily. How much sun is required as has been said depends on your location and type of skin (and is more of a problem when skin types drastically move location such as a very dark skinned person requiring more sunlight moving to Norway.)
www.kellymom.com/nutrition/vitamins/vitamin-d.html may help.
INFACT Canada Newsletter - ?Vitamin? D ? The Sunshine VitaminSome important Questions and Answers about infant nutrition and vitamin DQ. What is ?vitamin? D?
?Vitamin? D is actually not a vitamin at all, but a steroid hormone that was misclassified as a vitamin back in 1922 when small amounts were found to be naturally present in a few foods such as butter, the oils and livers of fatty fish and egg yolks. The hormone is known for its role in the calcification of bone tissue, but is also involved in the differentiation of cells for specific functions and acts as a powerful controller for the immune system; as well it helps to regulate insulin secretion and blood pressure. A deficiency in infancy can lead to a rare condition known as rickets or softening of the bones. Vitamin D is oil soluble and therefore is stored by the body for times of low exposure to sunlight.
Q. How do we get vitamin D?
Our main source of vitamin D is sunshine. Vitamin D is produced in the skin when it is exposed to the sun?s ultraviolet light (UVB radiation) and then converted in the liver and in the kidneys to the biologically active forms 25-hydroxy vitamin D and 1,25 hydroxy vitamin D. When exposed, the large surface area of our skin has the capacity to produce sufficient amounts of vitamin D in a short time well before sunburn can occur.
Additionally dietary vitamin D is sourced through breastmilk, fortified cow?s milk or other dairy products, liver and fatty fish.
Q. Is a deficiency in vitamin D common?
No. A deficiency in vitamin D is rare. We are hearing more concerns about vitamin D as people with darker skin and more melanin pigment to screen out UV rays from the sun immigrate to Canada from tropical countries.
A study published by the Hospital for Sick Children in Toronto reported2 only 17 cases during a six-year review from 1988 to 1993. The Canadian Paediatric Society, in a Press Release3 dated June 17, 2004 noted ?several cases? over a two-year surveillance. Their unpublished data reporting of a cross-Canada survey of 2300 paediatricians
note 69 cases over two years. In the US the Children?s
Hospital in New Jersey reported4 only nine cases over a three-year period.
Q. Who is at risk for developing vitamin D deficiency?
Risk factors for both mothers and babies for developing vitamin D deficiency and rickets include:
â– indoor confinement during daytime,
â– being covered with clothing while outdoors,
â– living at high latitudes with seasonal variation of UV radiation,
â– living in urban centres where high rises and pollution can block sunlight,
â– darker skin pigmentation,
â– use of sun screens.
Those screened to be at risk may benefit from prophylactic
vitamin D supplementation.
Exclusive breastfeeding is not a risk for deficiency; inadequate exposure to sunlight is the risk factor.
Q. How do infants get vitamin D?
The normal means for infants to receive vitamin D is through stores they receive prenatally; through skin exposure to sunlight and a small amount is also acquired from breastmilk. The amount in breastmilk can vary depending on maternal status. The amount in breastmilk should not be considered deficient as humans receive vitamin D through skin exposure to sunlight.
Q. How much vitamin D do infants need?
The amount usually recommended for infants less than one year of age is 200 to 400 IU per day.
Exclusive breastfeeding and skin exposure to the UVB radiation from sunlight is the normal way to get sufficient
vitamin D. The duration of skin exposure needed varies with skin pigmentation, time of day, season and latitude. The average recommendation5 of skin exposure for an infant is 30 minutes per week (wearing a diaper only) or a total of two hours per week fully clothed and without a hat.
Q. Is the recommended exposure to sunlight safe?
Yes. The short time exposure several times a week is a safe way to practise sun exposure and avoid burns. In addition to the benefits of vitamin D, scientists6 also suggest
that the safe use of sunlight is important for positive mental enjoyment and relaxation and possibly chronic disease reduction.
References
- La Leche League International. Press Release. Sunlight Deficiency, ?Vitamin
D,? and Breastfeeding. Schaumburg IL April, 2003
- Biet, A. et al. Persistence of vitamin D-deficiency rickets in Toronto in the 1990s. Canadian Journal of Public Health 87: 227-230, 1996
- Canadian Paediatric Society Press Release, Canadian Paediatric Society confirms rickets still a major health issue. June 17, 2004
- Sills, I. et al. Vitamin D deficiency rickets. Clinical Pediatrics. 8: 491-493, 1994
- Specker, B. Do North American women need supplemental vitamin D during pregnancy or lactation? Am J Clin Nutr 59: 4845-4915, 1994
- Ness, A. R. et al. Are we really dying for a tan? BMJ 319: 114-116, 1999
More interesting reading can be found at:
www.infactcanada.ca/Action_Alert_Vitamin_D.htm www.lalecheleague.org/llleaderweb/LV/LVAugSep03p75.html www.infactcanada.ca/breastmilk_and_vitamin_d_adequac.htm