My doctor says I need hair analysis to determine my nutritional status?

Your doctor is a moron. 

Hair analysis is not used to make determination of any illness in modern day medicine. Hair analysis is sometimes used to assess for drugs and heavy metal poisoning. There is no correlation between mineral content in hair to that found in blood. 

In simple, hair analysis is a crappy method for assessing nutrition. Hair analysis is an irreproducible science based on quack medicine. All you need is a change of your health care provider. 

If you do not have any sensible doctors in your neighborhood, then eat right, exercise regularly and do not smoke. Save your hard earned money for something more important like food and rent.