Would-be-fathers should eat more dairy products, orange juice, soya milk and cereals before planning a family, as a study finds that a father's vitamin D intake is associated with his child's height and overall health at the age of five.

According to researchers, a father's vitamin D intake during pre-conception can influence the health and development of his child. Dr Cilia Mejia Lancheros from the University College Dublin in Ireland conducted the study.This analysis investigated the prospective relationship between pre-conception paternal vitamin D intake and offspring height and weight.The team analysed 213 and 148 father-child pairs when children were aged five and nine years, respectively.

The association between father's vitamin D intake reported during the first prenatal trimester and the height and weight of children at age five and nine was calculated using a model adjusted for several possible confounders.The factors include — paternal age, energy intake height, weight, and being the biological father; maternal age, vitamin D and energy intake height, and weight; and child's sex, age, vitamin D and energy intake, and summer outdoor physical activity aged five.

Paternal vitamin D intake was positively and statistically associated with offspring's height and weight at five years old; whilst these associations were reduced, and no longer statistically significant when offspring reached nine years old.The findings remained similar when the analysis was repeated with only biological fathers.Interestingly, the findings showed no association between a mother's vitamin D intake during the first and second trimester of pregnancy and children's weight and height at either age five or nine years.

Skin exposure to sunlight is essential for the body to produce vitamin D, so the authors also looked at the number of hours children aged five spent playing outdoors during summer. They found that spending three or more hours playing outdoors during weekends was related to increased height at five years of age.They added, "One reason this may occur is that father's nutrition status may somehow influence the health, quality, and function of their germ cells, which are involved in reproduction".The research would be presented at this year's European Congress on Obesity (ECO) in Porto, Portugal.