It may be beneficial for both adolescents and adults to take vitamin supplements, such as vitamin D, during the winter months to prevent deficiencies. This is because we are often less exposed to the sun in winter, which can lead to lower production of vitamin D in the body. Taking a supplement of vitamin D3, at a dosage of 1,000 IU per day, can help ensure adequate levels of this essential nutrient. However, aside from changes in diet, winter typically does not bring about significant deficiencies in other vitamins and minerals.