The Finnish Vitamin D Trial (FIND) is a randomized, double-blind, placebo-controlled, 5-year supplementation study of the benefits and risks of vitamin D in the primary prevention of cardiovascular (CVD) and cancer among 18000 men 60 years or older and women 65 years or older.

[Edit 25.3.2015: Due to difficulties in recruitment and funding, the study size is approximately 2500 subjects, with a 550 subject subgroup with more detailed examinations]

The participants will be randomized to 3 groups with 6000 in each, with daily supplementation of either: 1) 40 µg/day (1600 IU) of vitamin D3, 2) 80 µg/day (3200 IU) of vitamin D3, or 3) placebo.

[Edit 15.3.2015: The 2500 subjects are randomized in 3 groups, approximately 830 subjects per group.]

Compliance, use of non-study drugs or supplements, diet, development of endpoints, and CVD and cancer risk factors will be assessed by questionnaires. Blood samples will be collected for assessment of effect modification by baseline 25-hydroxyvitamin D, as well as for future ancillary studies of genetic/biochemical hypotheses. Event data will be obtained by record linkage from the national computerized hospitalization registry.

More detailed description available upon request.

Inclusion Criteria:

• Men 60 years or older
• Women 65 years or older

Exclusion Criteria:

• Cardiovascular disease (including myocardial infarction, stroke, transient ischemic attack, angina pectoris, coronary artery bypass grafting, or percutaneous coronary intervention).
• Cancer (except non-melanoma skin cancer).
• Any disease or state that raises a vitamin D related safety concern (such as chronic liver, thyroid or kidney disease, hypercalcemia, sarcoidosis or other granulomatous diseases such as active chronic tuberculosis or Wegener's granulomatosis).
• Use of supplements yielding vitamin D over 20 µg/day or calcium over 1200 mg/day and unwillingness to discontinue the use.