What are the benefits and risks of supplementing with Vitamins D, E, A, and K (Vitamin D, Vitamin E, Vitamin A, Vitamin K)?

From the Guidelines

Vitamin D, E, A, and K supplements should be taken with caution and under the guidance of a healthcare provider, as excessive supplementation can lead to toxicity and other adverse effects. For general health maintenance, adults typically need 600-800 IU of vitamin D daily, with higher doses (1000-2000 IU) often recommended for those with deficiency or limited sun exposure 1. Vitamin E supplementation of 15 mg (22.4 IU) daily is sufficient for most adults. Vitamin A requirements are approximately 700-900 mcg RAE daily for adults, while vitamin K needs are about 90-120 mcg daily. These fat-soluble vitamins are best absorbed when taken with food containing some fat.

Some key considerations when taking these supplements include:

• Avoiding excessive supplementation, particularly with vitamins A and E, as they can accumulate in body tissues and potentially cause toxicity 2
• Being aware of potential interactions with medications, such as blood thinners, which can interact with vitamin K
• Considering individual health conditions that might affect vitamin needs or metabolism
• Recognizing that the content and concentration of ingredients in commercially available formulations can vary considerably, making it challenging to extrapolate results from controlled clinical trials 1

It's essential to prioritize a balanced diet rich in fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood, as adequate nutrition has been associated with a reduced risk for cardiovascular disease and cancer 2. Before starting any supplement regimen, consulting with a healthcare provider is crucial to determine the best course of action for individual needs and health status.

From the Research

Vitamin D, E, A, K Supplements

• The use of vitamin D supplements has increased substantially over the last decade, with epidemiologic evidence linking vitamin D deficiency to various illnesses, including autoimmune disease, cancer, cardiovascular disease, and more 3.
• Vitamin D supplementation is common in the United States, with about one-fifth of the adult population taking a daily supplement, although the beneficial effects of vitamin D sufficiency have only recently been established 4.
• Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D and various common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases 5.

Benefits and Risks of Vitamin D Supplementation

• The Institute of Medicine published a report in 2010 concluding that vitamin D supplementation for indications other than musculoskeletal health was not adequately supported by evidence, and that most North Americans receive sufficient vitamin D from their diet and sun exposure 3.
• Vitamin D supplementation may have anti-inflammatory and antioxidative effects, although the US Preventive Services Task Force concludes that the harms of beta carotene supplementation outweigh the benefits for the prevention of cardiovascular disease or cancer, and that there is no net benefit of supplementation with vitamin E for the prevention of cardiovascular disease or cancer 6.
• The Endocrine Society suggests empiric vitamin D supplementation for children and adolescents, those aged 75 years and older, pregnant individuals, and those with high-risk prediabetes, although the optimal doses for empiric vitamin D supplementation remain unclear 5.

Recommendations for Vitamin D Intake

• Expert recommendations for vitamin D intake differ between governmental agencies and practice guidelines from medical societies due to differences in the definition of vitamin D deficiency, insufficiency, and sufficiency based on serum 25-hydroxyvitamin D concentrations 7.
• The US Preventive Services Task Force recommends against the use of beta carotene or vitamin E supplements for the prevention of cardiovascular disease or cancer, and concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamin supplements for the prevention of cardiovascular disease or cancer 6.
• The Endocrine Society suggests against routine 25(OH)D testing in the absence of established indications, and recommends empiric vitamin D supplementation for specific populations, although further research is needed to determine optimal 25(OH)D levels for specific health benefits 5.

Other Vitamins

• There is limited information available on vitamins A and K in the provided studies, although vitamin E is mentioned as having no net benefit for the prevention of cardiovascular disease or cancer 6.
• Vitamins A, E, and K are not discussed in detail in the provided studies, which primarily focus on vitamin D supplementation and its effects on various health outcomes 3, 4, 5, 7.