Home About Breast Cancer Diet and Lifestyle Diet and Nutrition I’ve heard about vitamin D lately, can it help prevent cancer?

I’ve heard about vitamin D lately, can it help prevent cancer?

Apart from Vitamin D’s well known role in maintaining calcium balance for skeletal health, vitamin D is believed to be involved in the development of many cancers including breast cancer. Research has shown that vitamin D has an important role in regulating the way cells grow and divide, and in maintaining immunity, therefore vitamin D deficiency may have implications in the development of cancer.

A recent Canadian study showed that only 24% of women had adequate vitamin D levels at the time of their breast cancer diagnosis. The remaining women had either deficient (<50 nmol/L) or insufficient vitamin D levels. The study also showed that vitamin D deficiency was associated with a poorer prognosis.

Despite Australia having plenty of sunshine many people have inadequate levels of vitamin D. It has been estimated that 4-8% of adults in Australia have vitamin D levels below 28 nmol/L, levels considered mildly deficient. People at particularly high risk of vitamin D deficiency are the elderly, people who spend little time outdoors or fully cover their body, pregnant and lactating women, and those with darker skin colour.

Criteria for vitamin D deficiency

Adequate                              >72 nmol/L

Insufficient                         50-72 nmol/L

Mild Deficiency                25 – 50 nmol/L

Moderate Deficiency   12.5 – 25 nmol/L

Severe Deficiency              <12.5 nmol/L

 

The main source of vitamin D is from the conversion of ultraviolet light (UV-B) from the sun to vitamin D in our skin. In addition foods such as oily fish, eggs, margarine, and fortified dairy foods contain vitamin D. 

The recommended dietary intakes for vitamin D  for Australians and New Zealanders are shown in the table below. Adequate intake could also be achieved by spending 5 to 6 minutes in the sun with full body exposure in the summer months, or exposure of the face, hands and forearm to sunlight for 15-30 minutes, 2-3 times per week.

Recommended adequate intake (AI) of vitamin D

19-50 years                   5.0 mg/day

51-70 years                 10.0 mg/day

>70 years                     15.0 mg/day

Refs: (or should you put: Refs available upon request)

  1. Vitamin D and adult bone health in Australia and New Zealand MJA, 182 (6):281-285, 2005
  2. Goodwin P. Frequency of Vitamin D (Vit D) deficiency at breast cancer diagnosis and association with risk of distant recurrence and death in a prospective cohort study of T1-3, N0-1, N0 BC

3. Nutrient Reference Values for Australia and New Zealand including Recommended Dietary Intakes .  9-8-2005.  Australian Government Department of Health and Ageing, National Health and Medical Research Council.