Vitamin D is not strictly speaking a vitamin; it is more accurately a precursor to a hormone and has many important functions in the body.

The most known function is in calcium absorption, but it has many other roles including immune function and cardiovascular health.

Vitamin D deficiency causes some very serious conditions, such as rickets in children, and osteoporosis in adults.

Insufficiency has been associated with increased risks of:

• Various cancers
• Cardiovascular disease
• Multiple Sclerosis
• Rheumatoid arthritis
• Type 1 diabetes mellitus

The most important source of vitamin D is the sun; although we can get vitamin D from foods it isn’t enough to meet our needs and is considered a minor contributor. Foods that contain vitamin D include:

• Oily fish (e.g. salmon, mackerel, sardines)
• Irradiated mushrooms
• Egg yolks
• Cod liver oil
• Fortified foods (e.g. milk, juice, bread, cereal, margarine)

To meet our needs through sunlight various factors need to be taken into account, including: age, skin pigmentation, and where we live.

Recommendations for adequate vitamin D synthesis in Australia and New Zealand:

• 1/3 minimal erythemal dose (MED) of sun exposure to hands, face and arms most days

(MED  – amount required to produce a faint redness of the skin)

• Sun exposure during high risk times is not recommended, this is between 10am and 2pm (11am and 3pm during daylight savings)
• Take into account variations in season, latitude, time of day and skin type [1]

For people in climates that see little sunlight it is difficult to obtain the needed vitamin D, and supplementation may be necessary.

For people with chronic illness (especially bedridden patients) obtaining enough vitamin D may be difficult due to physical restrictions, getting outdoors may not be something done easily or often. If you are not getting regular exposure to vitamin D, a supplement may be needed.

Tips for getting out in the sun – for restricted people:

• Schedule outdoor time, ensuring it happens when someone else is home to help you in and out
• Do not put sunscreen on before you leave the house, try and get a bit of exposure and then apply it. You shouldn’t get burnt, just enough to feel the warmth and enjoy it for a short period. There is a risk of melanoma with sun exposure, it must be safe levels. A healthy exposure is the key.
• Expose hands, arms, and face when possible. If it is too cold save the outdoor trip for another day.
• Get someone to set up a chair in a good spot that you can easily get to, somewhere close to the house is ideal, and if possible avoid needing to use stairs to get to the seat (important for the physically restricted)
• Plan to do activities you would normally do inside outside, such as reading a book, or have your morning coffee outside.

Note for people with Lupus: Sun exposure can be a major problem for people with Lupus and could exacerbate symptoms. Lupus patients should keep sun exposure to a minimum, supplementation may be a good idea depending on severity of reactions to sunlight.

Reference:

1. Working group of the Australian and New Zealand Bone and Mineral Society, Endocrine Society of Australia and Osteoporosis Australia. Vitamin D and adult bone health in Australia and New Zealand: A position statement. MJA. 2005 Mar 21; 182 (6): 281-5.