Aim To assess blood vitamin D levels at time of cancer diagnosis in children, to supplement vitamin D where necessary, and reassess levels after 6 months of treatment.

Methods Newly diagnosed children had vitamin D, calcium [Ca], phosphate [P04] and parathyroid hormone (PTH) levels checked. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D (25[OH]D) level of less than 50 nmol/L, and vitamin D insufficiency was defined as a 25[OH]D level of 50–75 nmol/L. Children with levels <50 nmol/L were given cholecalciferol (6000 units/day >10 years, 3000 units/day <10 years) while children with levels between 50 –75 nmol/L received a lower dose (2000 units/day >10 years, 1000 units/day <10 years). Vitamin D levels were rechecked after 6 months.

Results Forty-four children (31 male, 13 female) aged between 4 to 19 years were studied. Twenty-six children were Caucasian and 18 were of Asian/African ethnicity. Only 16% [n = 7] of children had normal Vitamin D levels at diagnosis. The remaining 84% had either severe deficiency [n = 28; 64%] or insufficiency [n = 9; 20%]. Mean vitamin D levels in Caucasian children were 54 nmol/L compared to 35 nmol/L (p < 0.05) in African/Asian children. 50% [n = 13/26] of Caucasian children were considered vitamin D deficient vs. 78% [n = 14/18] of children of Asian or African ethnicity [p < 0.05]

There was no seasonal variation in the mean vitamin D levels; 44.6 nmol/L in autumn/winter vs. 47.8 nmol/L in spring or summer. Of those with vitamin D < 50 nmol/L, 3 had serum PO4 <0.89 and high PTH levels. In 2 children, with vitamin D <75 nmol/L, Ca was <2.15 nmol/L. Of the six children who have had 6 months of vitamin D supplementation, levels have normalised in four children [5/7 required treatment doses], and improved but not normal levels in two children One child who had normal vitamin D level at diagnosis but at 6 months, has become deficient [vitamin D <50 nmol/L].

Conclusion Vitamin D plays an import part in bone metabolism and may also have a significant role in immune surveillance. The majority of our children were vitamin D deficient at diagnosis with significantly lower levels in African/Asian children. Derangement of PTH, calcium or phosphate was rare.